If we were able to override version equality constraints then we would not have to download a stackage resolver's cabal.config file locally and comment out conflicting versions. This would work much the way stack allows its version overrides.

In 3.8 we will have conditionals and includes (including remote) in
cabal project files. So it will cover many use cases. However, we will
not yet have the ability to override constraints in included files. So
if you include a given lts, you will not be able to bump the version
of anything in the lts, outside of downloading and modifying its
freeze file, then depending on the modified freeze file.

Originally posted by @gbaz in #7556 (comment)