Short answer to your question,
"I'm always wondering, do the flares really make a difference? My gravel bike is really more of a do it all bike, shod with file treads, blocks, or slicks, depending on my mood....so while doing it all, flares or no flares?"
Depends, if you are comfortable, confident, and have total control that and you are happy with what you have, stick with what you have..
Long answer..
On my all purpose gravel bike I went from relatively standard 420 compact to 440 Ritchey VentureMax that have a 24 flare and a short drop. A standard compact bar always had me gripping the bars or mainly hoods hanging on hoping for the best. I'll never go back to standard bars. Flared bars totally transformed my experience with control, confidence, and capability. I do singletrack, on and off road centuries, and multiday tours with them and no regrets at all. In my opinion, for the most benefit of a flared/short drop bar you have to consider the best position of hoods and bar angle for riding in the drops. I went from almost never in the drops with my compact to almost always in the drops because of the control and comfort with the flared bars. I am far more comfortable in the drops now than I was in the hood before. Trying to get the best position for hoods AND drops is not easy, specially as the flare increases and the drop decreases (like the venturemax). If you try to setup the position of everything like a traditional bar for ultimate hood position you will be playing around a lot and the brifters will be all over the place. You should keep the brifter forward further down the drop and angled in on the top which may not result in the bar being on a level plane on the top but if you twist the bar to far up or move the brifter too far back to compensate there will be an angle or a valley between the bar and the hood and a drop that is angled up too far. If you have longer fingers you can reach a compromise. That's not to say you can't get it setup right but it isn't a compact bar shape so something has to be different
They are drop oriented bars first. The overall advantage in the design is using the wide flared end for control, hoods are secondary. I can totally understand why a lot of dedicated compact or regular bar users do not like flared. They are not regular bars with just the end bent out.
When I first swapped from compact to the flared, I swapped my stem for one +10mm that compensated for the shorter reach bar. I swapped back eventually and finalized by adding another spacer instead. Even with the shorter drop, I was mainly using the drops now and the additional height from the stem evened it all out. Depends on what you end up with but a stem change, angle, or height might be involved depending on where you eventually end up.