Trained ranks rejoining the regulars or joining the reserves don't do PRMC, although I have heard of a clueless careers adviser that mistakenly sent someone on one
When you contact the AFCO (or RMR unit, if joining the Reserves) just quote you wish to join under the 'Op Firefly 24' seamless transfer/rejoin scheme. You'll then hear someone scratching their head, wondering what that is, followed by a rustle of paper as they ruffle through a tower of recruiting instructions to check what you are on about. There's no joining bounty that I'm aware of & should join on the same pay increment you left on...double check you do, as errors are not uncommon.
If rejoining the regulars, you normally join CTC on a Weds, get re-kitted, respirator checks, undertake a BFT, weapons handling, assignment order, weekend off, join unit....
You'll probably get told there's a minimum return of service upon re-entry but in practice, you join on the AFPS 2015 contract and as a trained rank, you can bang your chit in day one if you want, but will probably not get early release, so will have to serve 12 months notice.
It should take less than a month to rejoin, but with Chrimbo leave upcoming, it could be Feb before you physically join.
At present, if you left as a GD, D3, Sigs, etc., there's every chance you'll rejoin as one and be subject to the same pings as everyone else.
Draft-wise, you can express a preference but as ever, expect to be sent wherever there's a pressing gap.
Any snags, shout out.