Hi Connor, I've just had another look at the patch.
PARENTSRC is really for DLL's that are going to reuse ~95% of the code. (d3dx9_*, d3dcompiler_* as example).
This isn't you case and I'm sorry I didn't pick it up first time around.
I guess patch 2 is showing the direction you want to head. I would start of with adding testcases and this may lead to the correct solution.
Maybe Henri can give some more advise.
Regards Alistair.