You don’t need to wait 52 weeks after certification, once a CPC, always a CPC, that’s straight from HR. I quit the agency 8 months after certifying. Also, there’s no wait on applying to OTS or prior experience bids once you’re out, speaking from experience. You can literally apply the next day if a bid is out. The only wait is the 1 year out of agency for CPC reinstatement, which I successfully did and did not have 1 year certified at previous facility.
To answer your question about how it would work reapplying to a prior experience bid as a former CPC, you will do everything same as all other applicants of the bid. Only difference is pay, which follows the CPC re-entrant guidance in the CBA: previous pay higher than new facility band = pay cut to the top of band, previous pay in the band of new facility = save pay (basic rate), previous pay lower than new facility band = pay raise to the bottom of new band.
Again, I went through this whole process short of receiving a list of facilities to rank since I had a reinstatement application being processed at the same time and ultimately approved.