When I first started running a suppressor on an SBR, my dealer told me that it was 'essential' that I have a switchblock on there, so I swapped out my existing gas block for the Noveske Switchblock. Well, the gun ran flawless in any of the three settings on the gas block. In light of that, I no longer run a switch block and the rifle (shock) runs flawlessly. I have never had a problem running a suppressor, regardless of barrel length, switchblock or not, caliber, etc. Suppressors make things quieter, that's the only change I've noticed in using them.

Back-pressure is slightly increased when using a suppressor but not enough that I feel the need to go back to having a switchblock for the gas.

Load, shoot, repeat.