It's funny...the one thing I HATE is watching the CPU constantly go to checkdowns. You said "balancing act" and you're dead-on....it's one reason I historically have loathed touching the RTP slider. But I have to confess, this setting is working out nicely....if their primary is open, they throw it to them. If not, they look to other guys. Once in a while I have seen even aggressive QBs check down when they "shouldn't"...but it isn't constant enough to be annoying.
FWIW, the functionality of the old IG slider is now wrapped into "defensive holding". It controls the jam at the LOS and the WR/DB interaction (the old IG did the same). In older EA games where QB aggression was crappy (looking at you, NCAA 14), I actually turned it off. Funny that we now use it (when it works) to disrupt that timing to deflate the passing game a tad.