If the goal is a regional, they should be looking for someone with a pulse.

If you have an instructor certificate, i'd polish it off and go flying.

Several months back I through in an application to Frontier for grins (currently on the outside of aviation myself). And despite my 25 hrs of 172 time in the last 6 months, I get a phone call from Republic offering me a class date...not an interview...a class date.

If you think you're going to end up back at a regional, I don't think it's going to take much experience to get you back there. If you have fractional/charter/135 experience and type ratings you might be able to nudge your way back in on that side...but they may be looking for more recency, and in many cases it's who knows you in those industries.

BTW - I'm about 2500 TT, 1900 T-121, 400 T-PIC 121.