Does anyone have any suggestions on how to tune the FD so that it will stop dropping the chain to the inside?
Ever since I got a Quarq Elsa power meter, I've been dropping my chain to the inside on average once per ride.
I've done what I can think of mostly, like adjusting the limit screw and fine tuning with the barrel adjuster. anymore of fidgeting with that, and the chain will rub when in the lowest gear.

And it's a pain because with the way that the Quarq spider is, once the chain drops, I'm pretty much guaranteed that I won't be able to pedal out of it. I have to stop, get off the bike, flip it over, and ease the chain out. The sensors on the spiders have edges that catch the chain if you try to pedal, and lock it in the BB well.

If messing around with fine adjustments to its angle doesn't sort it, you might have to resort to a chain catcher.

I tried a Deda Dog Fang, which kinda worked but not 100%... I think a SRAM-style one would be the go.

What FD are you using?

I'm having a k-edge chain catcher installed this weekend. I have a Shimano Ultegra FD.
I'm kind of worried though if I install a chain catcher, and it still manages to drop inside (people say that it's not supposed to, but i've heard that it happens), that I won't be able to get it out without taking off the chain catcher.

If it still happens then either you haven't set it up optimally or it's not designed well enough...

Nothing I tried made the Dog Fang work 100%, but it was still an improvement... except for when the chain did make it off the ring - it certainly didn't help when I had to put the chain back.

The difficulty in setting a chain catcher up is that it's virtually impossible to eyeball perfectly and often it's hard to get the chain to jump off intentionally; the best you can do a lot of the time is go and jump off gutters while downshifting.

Did your ring sizes change when you went to the power meter? Something must have changed, if it didn't drop the chain before.

Jump stop, K edge, or any of those sort of things keep the chain from going past the inside ring, entirely..

+1 for the N-Gear Jump Stop, I preemptively fit them to all of my bikes. Correctly installed there is no contact with the chain but there is no way the chain can be dropped; there is just no place for it to go.

Having said that make certain that the derailleur cage is set parallel to the chainrings and that your low limit screw is set to have the derailleur cage just barely clear the chain in the small front/big rear gear combination.

The chain ring sizes did not change with the power meter install. compact both. i checked the limit screws again last night, and had two drops today during my ride. once, i was climbing up a wooden bridge, and the second time i was descending down a shallow decline and shifted the rear derailleur, was already in the small ring up front, and somehow it popped off. must have hit a bump.
really getting annoying.

oh, i also have a compact, so wonder if maybe the distance to the small ring is just far? i didn't have any chain drops before the power meter install. the bike had a compact when i bought it. so not sure what is up with that.