When discussing additional devices, especially delaying devices, on doors with push bars it is important to realise why a push bar is fitted in the first place - it is a panic device, it's use resulting from countless deaths in years gone by not from the fire at all but due to crush injuries & asphyxia during evacuation.
Anything altering the function of the doors defeats the anti panic effect and increases the risk of injury or death and where the fire alarm system is vital in maintaining the panic function of the door by releasing, say, a mag-lock, it should be carefully maintained and managed - also what happens if there is a fault in the system or just part? Very few places seem to test the function of mag-lock relays, overrides, etc and only time will tell as to whether we are fussing about nothing or there is a genuine risk.
This isn't a new problem, except in days gone by it wasn't maglocks added but Redlam & Ashworth bolts (break tube release) added to panic exits with a perceived security issue.