A separate repo for HPL2 engine?

[Houkime]

it seems like both The Dark Descent and Machine For Pigs use the same HPL2.
And there is also a separate repo for HPL1 engine.

So it seems logical to separate HPL2 into its own repo (even if just to link it back via git submodules for codebases that rely on it being in a adjacent directory).
At the very least this way HPL2 won't diverge between TDD and MFP and .e.g. build fixes will apply to both.
Also a separated upstream makes it easier to package HPL2 separately for Linux if needed.

[TiManGames]

The engine MFP uses is a modified version of HPL2. While most of the engine is the same, there are some notable differences between the two versions. The Chinese Room made their own addition to the HPL2 engine, and so it has its own repository.

But yeah, there is probably a better way to structure both repos nonetheless.