To co-witness with standard height or OEM sights will require a milled slide so it sits low enough to be inline with the sights. Someone can correct me if wrong but I haven’t seen a RDS (yet) that is small enough to be mounted on a dovetail adapter plate AND co-witness w/standard height sights.
I’m running a Vortex Venom using a Outer Impact adapter plate on a M&P 9FS. It’s our first RDS and we’re still in the familiarization and practice phase. Still have standard height front sight and it’s not visible. I’ll buy a suppressor height set soon and use just the front. The RDS has rear index marks that should suffice as a rear sight if the RDS fails.