Procedure for updating GHC submodule pointer to Cabal

Hello all, I am working on module reexports (https://ghc.haskell.org/trac/ghc/ticket/8407) and this functionality requires concurrent changes to GHC and Cabal. However, GHC is currently tracking 1.20, but Cabal HEAD has marched on. My question is, if I am to do this development on HEAD, what is the standard operating procedure for retargeting GHC to a recent version of Cabal? Of course I have to go and validate the build, but are there any other considerations? Is this recorded anywhere? Thanks, Edward