As well as airsoft I've applied my irl experience to this, nearly 40 years ago we didn't have plate carriers, it was 58 pattern, essentially belt & braces kit, but the materials were heavy & got heavier when wet, so I remember switching to belt kit, mainly yank equipment, when ever I could get away with it, army rules & regs etc meant anything involving above platoon or maybe company level would get you a bollocking or worse.
Back then the belts weren't padded, but I had a waist, & blousing your smock gave you a bit of padding to stop things rubbing, assuming you weren't overloading your belt order.
Fast forward to when I started airsofting, PC was one of my first purchases, but I soon realised that unless your fitter than a butchers dog, wrapping your core in all that heavy duty nylon/corduroy will soon have you sweating like Jimmy Saville in an orphanage, plus all that molle MUST be filled, it's the law, so i soon changed to chest rig, type with an open back & not too much coverage on the front, bulle mle remains my favourite, although I've got plenty of others.
Still trying to get back in to belt rigs but middle age spread has meant I've lost a defined waist, so unless I run it super tight (which aggravates my dodgy lower back) it will slip down a bit.
Alternatively, grab bags, or looking at helikon tmr etc could be a consideration, smaller rigs will force you to reconsider what you carry in game, which in turn should alleviate some of the pressure on you back.
IMHO🤔