Yes - it will fit. The screws are different since the Holosun requires shorter screws. If you order the RMR plate you’ll have to find different screws… and they have been discussed at length here.
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When I said “here”, I meant pistolforum. I’m not sure what specific optic thread… that said the screws I use for the Staccato/Dawson DPO plates are McMaster Carr stainless 6-32 but I need to get my hard drive to get the exact measurement/item number. I just used them to re-mount my 407C on my Staccato P that came back from some warrantee and add-on work.
Optic screws are not necessarily the same across different plates. Some plates may be threaded for different screws such as 6-40 or the plate may be thinner (requiring shorter screws) or thicker (requiring longer screws). There isn’t a ton of standardization right now.
I pulled up my info... The screws I use for Holosun (407C/507C/508T footprint) to the Staccato (Dawson) plate are as follows:
McMaster-Carr 6-32 x 3/8" Stainless Steel (IP10 Drive), part number 92703A253.
I use stainless instead of alloy steel because the Holosun optics require a smaller diameter head than the RMR/SRO and the stainless fits while the alloy steel are too wide to seat consistently, especially with the titanium body 508T.
Between the Holosuns and the RMR, there's a 1/16" difference, so whatever any plate requires for RMR screws, take 1/16" off that and you'll have what you need for a Holosun.