That is probably a good idea, and I might try it if my homemade gasket also fails. When I made the new gasket, I left more "meat" in the areas where the commercial gaskets would fail. The polycarbonate SHOULD be a lot stronger than the paper gasket it replaces.
So far it seems to be working fine. If the polycarbonate gasket fails, I might try making one out of soft copper sheet.
I have wondered why the gaskets kept failing. Maybe there has been erosion in that spot on the pump body, although I could not see or feel anything that worried me. Some years ago, I replaced the hydraulic relief valve with one from the aftermarket. I am wondering if that valve has stuck and the system is getting over pressurized. Then next time I drain my hydraulic oil I think I will put the original relief valve back in, assuming I can find it. When I changed the relief valve, it did not change the symptoms I was trying to fix.
Thanks for your input!