Is pressure canning, weeks after regular canning safe?
I can't come up with a way to do this that is not problematic.

First, no canning authority I can find provides instructions on how to re-can under pressure food that is already canned.  The closest instructions I can find are from the national center for food preservation, which basically say "don't do it".

Second, you're talking about a month between initial canning and then re-canning under pressure.  A month is plenty of time for botulism spores and other toxic microorganisms to germinate, which really only need a couple of days, so you'd need to keep the jars in the fridge.  Given this, it would be tempting to roast the peppers and not process them at all and just keep them in the fridge, but again in that amount of time they would get moldy (and certainly lose flavor).  Freezing them would destroy their texture.

Third, this means you would be running the full jarring process twice, which would almost certainly result in soft, mushy peppers.  You can't cut the time on either proccessing cycle, because without the full cycle neither would be safe.  I suspect that you'd also have a high ratio of jar/lid failure.

Let me suggest an alternative: package your peppers in a hot water bath, now, with added citric acid.  Raising their acidity makes them safe to be jarred at air pressure, and they will still be pretty good.  Save the pressure canner for next year.