This is the information provided by TriggerTech for compatibility in regards to safety selectors:
"Which Safety Selectors are compatible with TriggerTech?
While we try to accommodate a wide range of tolerances in our design the challenge with AR15 Safety Selectors is that there is no standard for them (they are not part of the M16/M4 Technical Data Package). It is very import to follow step 5 of 7 in our Installation Guide (With the Safety Selector installed and in the SAFE position, use the 1/16” Allen key supplied and FIRMLY tighten the two snug-down screws towards the back on the trigger housing). Having the safety selector installed and in the SAFE position prior to tightening should result in an idea fit between the Safety Selector and the transfer bar of the trigger. While TriggerTech is compatible with nearly all common selectors, some slight fitting may be required and in some rare cases TriggerTech may not be compatible with a given Safety Selector."