jrcollins:
Does anyone have any experience with this type of face plate and mounting block?
https://www.pbtech.co.nz/product/ITPFPKS002/Dynamix-FP-2KS-Dual-Port-RJ-45-Keystone-Face-Plate
Can they be screwed directly into plasterboard?
Yes, it has the 4 holes in the corners that are used for direct fixing.
I usually use these type anchors under them.
But if youre not getting massive amounts for cheap, then a C clip ends up being cheaper than 4 of them. I have never had any luck with just screws into gib.