I have several pairs of the padded equine underwear. Horrid things, feel like you've got half you underwear drawer shoved down your knickers but in the saddle they are comfortable. I used to get horrendous saddle sores - changed my saddle to a wow and all those big knickers now make great dusters.
I only own thongs! Well apart from a few pairs of very unsuitable french knicker things, which are rarely worn outside the house
But made the mistake of doing a day long 25 mile hack wearing a thong - literally still bear the scar from the cut that resulted. Couldn't sit down without pain for about a week.
Big knickers all the way a size too big works wonders. For shows I have girlie boxers/shorts type thingys very comfortable!
Sod having a VPL comfort is far more important!
Had to explain to OH a while ago that I was a bit sore due to
unsuitable underwear! All he did was laugh!