Shirley a quality set of orthopaedic insoles are all that’s needed? No boot or shoe, other than custom-built, will have anything other than a flat footbed, none that I’ve bought have, support is supplied by whatever insole is inserted by the manufacturer.
Even the Meindle Desert Fox boots I wear need different insoles, I find the standard ones a bit too flat and hard.
On that basis, Muckboots with a decent, properly designed supportive insole should absolutely fit the bill, they’re fantastically comfy, I wear just regular cotton sports socks in mine, with neoprene boot socks over the top, and I’ve walked eight or nine miles in mine.
Which reminds me, I need to put mine back in the boot of my car, just in case I need them for a wet afternoon walk.