If the defender has access to a reversal, they might be more likely to use it if they have; a meterless followup, a happy birthday opportunity, or a safe dhc. If burst sparks are triggered immediately prior to a mixup, the attacker reduces the risk against pre-emptive reversals to being put back into neutral. If the defender's reversal would only have put them at neutral then a trigger into mixup is a tradeoff; if the defender's meter is important, a burst is worse for the attacker, but if the attackers health is more important the burst is better for the attacker.
example: Peacock wants to reset a solo Cerebella. If she goes for a low/throw, bella has access to 360 into combo, which would be a nasty turn around. Triggering ips first as a tick into low/throw improves that risk reward for peacock. If she goes for an instant overhead, Bella has access to battle butt and dynamo, which do a chunk of damage but bring it back to neutral. If Peacock is low health then an ips trigger will help mitigate the risk of dying to the reversal, but if Peacock has health to spare, not triggering first might get Bella to spend her meter, reducing her options.
If the defender has high health and the undizzy bar is full, getting hit by a mixup is a smaller threat, so they should be less likely to press buttons. Some things that encourage button presses would be ground tech opportunities, lockdowns, or other obvious pushblock points.
Example: A painwheel/double has taken a solo squigly to 70% life and wants to reset. If squigly gets hit by a throw or an assist crossup, the damage won't be much at all, so they should be happy to try to block on reaction. Since squigly will likely be a passive defender, Painwheel can use feints to make a mixup harder to read; moving left and right above squigly's head before choosing which side to come down on, or landing and flying or delaying slightly. Painwheel might also try to convince squigly to press a button by jumping in and calling assist to threaten a lockdown, then cancel into fly to bait a potential pushblock.
Conversely, if the defender is low health, the difference in damage from a counterhit doesn't matter, so they should be more willing to be active on defense.
Another thing is with safe dhc's a safejump setup isn't as good for the attacker compared to burst baits or trigger into mixup.