I struggle with those inserts, once my feet start swelling I need all the room I can get & the padding takes up space!
if you use them, take extra body tape with you in case it comes away from the shoe, they shouldn’t be bunching under your toes - they’re either not in the right place or they aren’t sticking firmly enough.
I find support tights help, m&s do nice ones with a sheen that aren’t granny-fied.
as an absolute last resort and this isn’t something you should do all the time, it’s a bad idea but it does work, deep freeze spray for injuries helps you get through that last hour in painful heels but do not do this daily, or if you’re steaming drunk, nobody wants a shattered ankle from not being able to fully feel their foot and falling over on the dance floor.
the best heels for all day are the ones that are built with the shoe heel under the centre of your foot heel, it distributes weight more evenly than the shoes where the heel is level with the very back of your heel.
if you can afford it, having the shoes re-soled at a cobbler (Timpsons) in leather instead of plastic really helps but it’s not cheap. LK Bennett did nearly all their heels in leather soles and even when they’re higher than a pair from next or dune they are SO much more comfortable.
the only other thing is I do find if I slip them off for a second it’s unbearable putting them back on, so if you’re determined to see it through to the end, try to keep them on even if you only slip your heels and arches out for a bit under the table