I agree completely that a DT should be able to put up around 25 reps but I can be somewhat flexible for guys with long arms. They need that kind of strength to face up against guards and double teams regularly, especially if he plans on being decent against the run. If Nolen's numbers match up with what you have listed, I will be on board if that's the direction the team goes. I will just consider it a sign that they want to move on from Dexter, who does have great lower body strength but his upper body strength was subpar his first couple of years.
Kiran has a wingspan on him, I think Dexter has something like 32" arms on him.
Dexter isn't a bad player and has value in a rotation, especially in a year where if the Bears do draft another DT or two they're going to spend their rookie seasons perfecting their run defense like all rookie DTs, above all else.
After Tommie Harris tore his hamstring from the bone I've hoped that the Bears would adress the DT position with a top tier rotation instead of putting all of their eggs in one basket with a dominant starting tandem and Ian Scott with Alfonso Boone as a backup plan.
If they add Nolen and Tyliek Williams with Dexter and Billings that's a God damn good DT rotation for any roster that will change the entire landscape of your rosters defensive play. There's no let up there. If you were able to keep Dexter with Nolen and Tyliek Williams long term then that's a proper spearhead of any 4-3 defense.
If you ad those two players on the interior, I don't care if they are stuck developing Booker off the edge, they're going to be tough to beat.