I'm far from an expert but I'm trying to picture how using Aerobars would cause PF symptoms to flare up? I'm not trying to be sarcastic, I know the angles all change a bit, but is the stress on your foot that different?

torso bent more, so there's more pull on top from the glute on the hamstring. same thing down below, feet are pushing hard and the hamstring is tight so its pulling up on the PF. ... its weird - honestly. biking I feel good on top of the bars, the hoods etc. But then I'm doing a brick and its after the bike that my PF hurts - not the run...

Maybe your seat is too high.

Sounds like it could be a fit issue. Are you using a road bike with long tri aero bars rather than shorter road geometry bars?

I'm guessing from the post that you have a race coming up.
I say leave the aerobars on... and use them in the second half/last third/quarter etc of the ride. If when you start using them your foot starts hurting stop.

This isn't based on any actual experience or knowledge on my part. It does seem to make sense, though. And I don't think that the extra weight of the bars is gonna make that much of a difference in the first part of the race.

Sometimes riding hills aggravates my achilles so maybe the hills caused your PF to flare up. Just a guess.

road fit, visiontech xs bars. (shorter than the "small" syntace bars). I probably could fit on a shorter stem but that's a whole other experiment waiting to get figured out...

Hmm... not a bad idea. The other problem with these Visiontech bars is that they block the top bar VERY effectively. (sucks for my natural mode of climbing) I guess I'll think about it...

ps. as for the seat being too high; I doubt that - if anything I want it higher... and hills causing problems... well, as far as I remember the course I'm doing (Guelph) does have some hills in it...