Two options that I can think of:
1) Take off the soft armor vest and run the PC when needed
2) instead of a PC get an armor carrier like the Mayflower/Velocity Systems LPAC and wear the armor carrier sans plates and add plates when needed
When I was in patrol I wore a concealment vest and wore the PC outside the uniform when it was needed.
Now that I'm in a specialized unit I wear my soft armor in an outer vest. Plan is that if I immediately need the PC I just doff the armor and go with the PC. Again, remember you are losing coverage for most threat rounds (pistol caliber) when only wearing plates. It's a risk.
I couldn't imagine wearing plates on 99% of the calls. Your back is going to kill you and being seated for extended periods of time with two plates is going to be super uncomfortable