Is it dangerous to shoot a round that is slightly deep seated?

YES!

No quibbling about what does "slightly" mean, yes, it can be (is) dangerous.

Depends on how bad the set-back is. If the pistol is a modern handgun, in good working order, a very slight setback, (1-2mm's) is NOT going to hurt anything if it's quality, factory loaded ammunition. I've fired such ammo in Glocks, M&P's, and 1911's. After a slightly noticable set-back, (again, MORE THAN 1-2mm's), I remove the round from the magazine and put it in a MTM bullet box and shoot it the next range visit. When I used to load/unload my carry pistol everyday, (G27), I went thru a lot of 165 & 180 grain Gold Dots destined for said MTM range box. All it took was 7-8 chamberings to cause noticeable set-backs in that pistol. Now if we are talking about a round that is 3-5milimeters set back... I just threw them in the trash! OP, you said slight set-back so I guess that can be subjective. That's why I gave a relative millimeter measurement for reference. Yes I have a caliper and maybe it's time for you to have one. If the setback is very noticeable then simply throw them away. It's not worth finding out if the pistol will safely shoot them. For me now, once a pistol is loaded, IT STAYS LOADED and rarely gets unchambered until shot. So I put almost zero ammo in the range box now to be shot up next range visit. Having 1 master safe for long guns/pistols/& ammo, & and (2) Gunsafe Delux fast access pistol safes, (one on each level of the house), helped with this. As it secures the carry pistol off my belt and the HD pistol from little hands. It has a siren that screams if said little hands get curious and locks the safe up. You can only unlock it with a key...

I find Ranger B's, and HST's to have a better crimp and are under less subjection to setback from multiple chamberings. Ball ammo, Gold Dots, and Hornady XTP's seem to setback even in M&P's, (the least offender of all handguns IME), after multiple chamberings. Get some calipers so you can be sure... If your shooting 40 caliber then really pay attention to it as they seem to be a little more susceptible to setback than other polymer platforms...

I believe the American Rifleman's article on this subject mentioned that if 9mm bullets are setback .100" into the case, then the pressure doubles.

IIRC

So, watchout.

A quick check is stand it up beside a known good round from the same batch. If its shorter, take it out of the batch. Measure per the above advice and don't fire it if set-back is greater than 2mm. Here's how I work it in my carry guns; I load a round and leave it there until either I shoot the pistol or unload it for some reason. If the chambered round looks okay, I hold it out until I reload the pistol. I put the loaded mag in it and the next round, then drop the mag, empty it, put the previously loaded round in first, top off the mag and lock it in. In this way the previously loaded round is the last round.
If the round had visible set-back when unloaded from the chamber, it would not be re-used except possibly at the range, depending on how bad the set-back is.
The best thing is to avoid set-back in the first place by fixing the pistol so it loads easier. The easiest and sometimes the most effective thing you can do is first clean the feed ramp then put a little drop of gun oil on it and rub it in with your finger tip.