I found this. I think it's been posted here before, but I'd forgotten the details. Apparently it's a similar footprint, but bosses likely need to be removed and reduced. Life is harder than it needs to be.
https://optics-info.com/footprints-on-red-dot-sights/
A modification of the Shield standard
Important Notes
Holosun 407K and Holosun 507K feature a modification of the Shield footprint. The differences are:
the two rear sockets are missing
the sockets in the front are shallower
For this reason, some pistols that are optic ready for Shield footprint need to be modified for the 407 and 507K. Namely, the two rear indexing lugs on the pistol have to be removed and the two front indexing lugs shortened in height. Hellcat and Walther PPS are examples of such pistols (some pistols, such as Sig Sauer P365XL, do not have to be modified).