Anything within the limits of the UPA is fair game. If the MEC has issues with this, they can engage the company on it. You should talk to your LEC reps and explain that you want modifications to the UPA regarding PPU.

Keep in mind that PPU is a “get” for the pilot group. The company did not want to have to potentially pay double for someone to fly a trip, as well as possibly having to drop another trip and pay protect for that as well. Having just taken a substantial pay cut from WB left to WB right, I will certainly be utilizing PPU if the opportunity arises. The company has never recalled pilots because pilots refused to fly, and if all of a sudden pilots stopped doing PPU, they would take ALPA to court for violating the status quo.