For wearing under baggies, rather than “Proper” under-shorts I prefer to use the cheap (Decathlon) padded Lycra shorts or bibs, a proper pair of Lycra shorts won’t shift about, so the pad stays where you want it, I’ve also got an old set of Shimano Bids with lots of life left in the pad but the Lycra is wearing a bit transparent in the arse area, perfect for use under baggies
I tried the Endura padded Boxers myself a long while back, they were not particularly great, they are basically a pair of baggy cotton boxers with a thin pad sewn in the crotch, they are essentially designed to chafe your gentleman’s region to bits… that put me off “Under-shorts” and persuaded me Lycra was the way to go…