Re: Spare tire and accessory mounts for topper cage
I would look to make sure the cap is rated to handle the weight. Some of those caps can't handle much. Some can. I'd hate to see you go to all the trouble only to have the weight break things.
As I get closer to being an "old fart", the prospect of lifting a tire up that high becomes less appealing. And the wind resistance will drop your gas mileage. But if those things don't bother you, there's no reason not to put it up there.
One alternative to having a spare all the way up there is to have a tire mount in the bed up against the bed rail. That wouldn't be as high up to lift. And it keeps it out of the weather. But if you're going to use all of the bed and don't have room that won't work.
2021 JLU 3.0D/8HP75/NP241OR/D44/D44
1987 MJ 4.0 (or 4.6)/AW4/ORD Monster Box/NP205/HP60/D80 on 40's with ARBs (that's the plan anyway, ETA 2022)
If you can't fix it with a hammer or duct tape you have an electrical problem