Do privacy rules allow you to discard filters in RGs?

Yep… privacy rules are a “filter” themselves that are applied at the server level. So you don’t need to replicate them in a RG filter.

In terms of the impact on performance, if your RG search is at the server level (the stuff in the “Search for” box), then there’s probably not much of a speed difference. But if the RG search is client-side (usually, stuff in “:filter”) then yes, it should speed things up.

And also… for full clarity, any RG filters being used to limit data shown aren’t truly secure. Someone with tech knowledge can get around it. Thus the importance of setting privacy rules.