diff --git a/src/Handler/Firm.hs b/src/Handler/Firm.hs
index 53914269e..b50539d87 100644
--- a/src/Handler/Firm.hs
+++ b/src/Handler/Firm.hs
@@ -517,7 +517,48 @@ mkFirmAllTable isAdmin uid = do
                   E.||.  (usr E.^. UserSurname      `E.hasInfix` E.val criterion)
                 )
             )
+          -- THIS WAS WAY TOO SLOW:
+          -- , single ("is-supervisor" , FilterColumn . E.mkExistsFilter $ \row (criterion :: Text) -> do
+          --     (usr :& usrCmp) <- E.from $ E.table @User
+          --       `E.leftJoin` E.table @UserCompany
+          --       `E.on` (\(usr :& usrCmp) -> usr E.^. UserId E.=?. usrCmp E.?. UserCompanyUser)
+          --     E.where_ $ ((usr E.^. UserDisplayName  `E.hasInfix` E.val criterion)
+          --           E.||. (usr E.^. UserDisplayEmail `E.hasInfix` E.val (CI.mk criterion))
+          --           E.||. (usr E.^. UserSurname      `E.hasInfix` E.val criterion)
+          --       ) E.&&. ((E.isTrue (usrCmp E.?. UserCompanySupervisor) E.&&. usrCmp E.?. UserCompanyCompany E.?=. queryAllCompany row E.^. CompanyId)
+          --           E.||. E.exists (do
+          --               usrSpr <- E.from $ E.table @UserSupervisor
+          --               E.where_ $ usrSpr E.^. UserSupervisorSupervisor E.==. usr E.^. UserId
+          --                 E.&&. E.exists (do
+          --                     usrSub <- E.from $ E.table @UserCompany
+          --                     E.where_ $ usrSub E.^. UserCompanyUser    E.==. usrSpr E.^. UserSupervisorUser
+          --                         E.&&.  usrSub E.^. UserCompanyCompany E.==. queryAllCompany row E.^. CompanyId
+          --                   )
+          --             )
+          --       )
+          --   )
           , single ("is-supervisor" , FilterColumn . E.mkExistsFilter $ \row (criterion :: Text) -> do
+              usr <- E.from $ E.table @User
+              E.where_ $ ((usr E.^. UserDisplayName  `E.hasInfix` E.val criterion)
+                    E.||. (usr E.^. UserDisplayEmail `E.hasInfix` E.val (CI.mk criterion))
+                    E.||. (usr E.^. UserSurname      `E.hasInfix` E.val criterion)
+                ) E.&&. (E.exists (do 
+                      usrCmp <- E.from $ E.table @UserCompany
+                      E.where_ $ usr E.^. UserId E.==. usrCmp E.^. UserCompanyUser
+                        E.&&. usrCmp E.^. UserCompanySupervisor
+                        E.&&. usrCmp E.^. UserCompanyCompany E.==. queryAllCompany row E.^. CompanyId
+                    ) E.||. E.exists (do 
+                      usrSpr <- E.from $ E.table @UserSupervisor
+                      E.where_ $ usrSpr E.^. UserSupervisorSupervisor E.==. usr E.^. UserId
+                        E.&&. E.exists (do
+                            usrSub <- E.from $ E.table @UserCompany
+                            E.where_ $ usrSub E.^. UserCompanyUser    E.==. usrSpr E.^. UserSupervisorUser
+                                E.&&.  usrSub E.^. UserCompanyCompany E.==. queryAllCompany row E.^. CompanyId
+                          )
+                    )
+                )
+            )
+          , single ("is-supervisor2" , FilterColumn . E.mkExistsFilter $ \row (criterion :: Text) -> do
               (usr :& usrCmp) <- E.from $ E.table @User
                 `E.leftJoin` E.table @UserCompany
                 `E.on` (\(usr :& usrCmp) -> usr E.^. UserId E.=?. usrCmp E.?. UserCompanyUser)
@@ -526,16 +567,22 @@ mkFirmAllTable isAdmin uid = do
                     E.||. (usr E.^. UserSurname      `E.hasInfix` E.val criterion)
                 ) E.&&. ((E.isTrue (usrCmp E.?. UserCompanySupervisor) E.&&. usrCmp E.?. UserCompanyCompany E.?=. queryAllCompany row E.^. CompanyId)
                     E.||. E.exists (do
-                        usrSpr <- E.from $ E.table @UserSupervisor
+                        (usrSpr :& usrSub) <- E.from $ E.table @UserSupervisor `E.innerJoin` E.table @UserCompany `E.on` (\(usrSpr :& usrSub) -> usrSpr E.^. UserSupervisorUser E.==.  usrSub E.^. UserCompanyUser)
                         E.where_ $ usrSpr E.^. UserSupervisorSupervisor E.==. usr E.^. UserId
-                          E.&&. E.exists (do
-                              usrSub <- E.from $ E.table @UserCompany
-                              E.where_ $ usrSub E.^. UserCompanyUser    E.==. usrSpr E.^. UserSupervisorUser
-                                  E.&&.  usrSub E.^. UserCompanyCompany E.==. queryAllCompany row E.^. CompanyId
-                            )
+                          E.&&.    usrSub E.^. UserCompanyCompany       E.==. queryAllCompany row E.^. CompanyId
                       )
                 )
             )
+          , single ("is-default-supervisor" , FilterColumn . E.mkExistsFilter $ \row (criterion :: Text) -> do
+              (usr :& usrCmp) <- E.from $ E.table @User
+                `E.innerJoin` E.table @UserCompany
+                `E.on` (\(usr :& usrCmp) -> usr E.^. UserId E.==. usrCmp E.^. UserCompanyUser)
+              E.where_ $ ((usr E.^. UserDisplayName  `E.hasInfix` E.val criterion)
+                    E.||. (usr E.^. UserDisplayEmail `E.hasInfix` E.val (CI.mk criterion))
+                    E.||. (usr E.^. UserSurname      `E.hasInfix` E.val criterion)
+                ) E.&&. usrCmp E.^. UserCompanySupervisor
+                  E.&&. usrCmp E.^. UserCompanyCompany E.==. queryAllCompany row E.^. CompanyId
+            )
           , single ("foreign-supervisor", FilterColumn $ \row (getLast -> criterion) ->
               -- let checkSuper = do -- expensive
               --       usrSpr <- E.from $ E.table @UserSupervisor
@@ -570,8 +617,10 @@ mkFirmAllTable isAdmin uid = do
         dbtFilterUI mPrev = mconcat
           [ fltrCompanyNameUI mPrev
           , prismAForm (singletonFilter "company-number")                             mPrev $ aopt textField (fslI MsgTableCompanyNo)
-          , prismAForm (singletonFilter "is-supervisor")                              mPrev $ aopt textField (fslI MsgTableSupervisor)
           , prismAForm (singletonFilter "is-associate")                               mPrev $ aopt textField (fslI MsgTableCompanyUser)
+          , prismAForm (singletonFilter "is-supervisor")                              mPrev $ aopt textField (fslI MsgTableSupervisor)
+          , prismAForm (singletonFilter "is-supervisor2")                             mPrev $ aopt textField (fslI MsgTableSupervisor)   -- TODO: remove either one variant which works worse
+          , prismAForm (singletonFilter "is-default-supervisor")                      mPrev $ aopt textField (fslI MsgFirmSuperDefault)
           , prismAForm (singletonFilter "foreign-supervisor" . maybePrism _PathPiece) mPrev $ aopt (boolField . Just $ SomeMessage MsgBoolIrrelevant) (fslI MsgFilterForeignSupervisor)
           , prismAForm (singletonFilter "company-postal"     . maybePrism _PathPiece) mPrev $ aopt (boolField . Just $ SomeMessage MsgBoolIrrelevant) (fslI MsgFilterFirmExtern)
           ]