Shortcomings in dependency analysis of deriving clauses

{-# LANGUAGE DerivingStrategies, GeneralisedNewtypeDeriving #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE UndecidableInstances #-}

module T23496 where

import Data.Kind

class C a where
  type T a :: Type

instance C Int where
  type T Int = Bool

newtype N = MkN Int
  deriving newtype C
--deriving instance C N

--instance C N where
--  type T N = T Int

type F :: forall a. T a -> Type
type family F a where
  F @Int True  = Float
  F @N   False = Double

With either of the derived instances (standalone or non-standalone), we get a type error:

error: [GHC-83865]
    • Expected kind ‘T N’, but ‘False’ has kind ‘Bool’
    • In the second argument of ‘F’, namely ‘False’
      In the type family declaration for ‘F’
   |
28 |   F @N   False = Double
   |          ^^^^^

Changing it to an user-written instance (comment out the deriving clause and uncomment the instance), the program compiles fine.

I think the problem is that we separate out derived instances from user-written instances in tcTyClsInstDecls; they should instead be handled together as they might depend on eachother.