One of my striker-fired pistols require the trigger to be pulled in order to remove the slide. I first move the slide back a little, pull the slide release buttons down and then I have to pull the trigger to release the slide. So far, I’ve never had a jammed cartridge, but would you recommend putting something in front of the primer, just in case? I’m pretty sure the firing pin won’t reach the primer with the slide back, but I don’t know. I’d think this is a time to err on the side of caution.
I did have a slide on a different pistol get stuck on a FTE due to an extractor problem, as I found out later. I was a little nervous because I hadn’t been counting rounds and I didn’t know if there was one in the chamber. In that case, a little hard rapping, with the barrel pointed downrange, jarred the case loose enough to free the slide. It wasn’t loaded, but sometimes you just don’t know.
In your case if i suspected a stuck round, I would first try placing an empty magazine, then pulling back the slide. Unless it’s one of the cheapest of the cheap it will lock to the rear and you can extract the cartridge that way.
If you *must* pull a trigger on a live round, use the same rule as you would if firing at a target— ensure you are pointing it in a safe direction.
BTW a thick paperback book is a safe backstop for point-blank firing up to .30-06. You may be able to guess how I know. I say “up to” because I never tried anything bigger :)