I can't directly answer your question but I am waiting on CGW to complete milling my SP-01 for a non rear sight adapter plate and to install an SRO. I should have it in hand in a couple weeks and will report back. In the meantime, I've also just sent my P10C slide to Primary Machine to be milled for a Holosum 507C and for a camo cerakote job. Again, I can report back. More to your question tho, I also have a PCR I want to mill for a RDS and asked the CGW folks what RDS they'd recommend given the small/narrow PCR slide. Dave's verbatim response: "The Shield RMS is pretty bitchin' for the compact CZ's. Fits and works great on a compact CZ." Just some food for thought if you're not wedded to the Holosun.
Cheers!