I put that Galloway Seneschal Short Stroke Trigger in my Security 9 and ended up taking my Drimmel tool to it to grind off the edges of the center trigger safety arm. Nice trigger but sharp edges need to be rounded before use.
I hope I don’t have to do that to mine but i will if I have to.
There are a lot of things you don’t have to do, but keeping smooth edges is very handy. When I take a firearm down for the first time I will smooth and polish anything I can especially if the case touches it.
I installed the Galloway trigger and do not like it. First off, if I don’t pull straight back on the trigger it can bind up and not release the hammer. Not qood thing if you are in a stressful situation. Secondly, the trigger safety toggle digs into my index finger and hurts my finger. I sent it back for a refund.