3rd gen Canopy / topper questions... stupid or not so?

Hi all.

Newbie on the site here and as always, sorry if this has been posted but did have a scan through.

I have a 23 TRD ORP and getting into the overland spending pit. Ive got as far as the roof racks and bed rack (along with a few other items) in prep to eventually buy a RTT later this year for some adventures with the missus and 2 dogs.

What Id like to ideally do for that reason is get a topper or canopy that can support a RTT whilst below we can chuck the dogs in overnight and know they cant get out and nothing can get in. I had a scan, seen various videos of LEER options for a topper but im on a bit of a budget. As mentioned I have a bed rack currently installed and wanted to know your thoughts out there, if it would work or is even possible or been done.

Im looking (instead of spending close to $5000cad for what Im after) to buy a topper for my short box, nothing too fancy as the pre owned sales are very reasonable here. But then install the bed rack framing internally, bolting it to the topper so once a RTT is installed it can take the weight of that and support it onto the bed itself. Ive just noticed since the bed racks been installed, economy has gone down somewhat so for the days when its not in use it still has some function rather than an empty bit of lego technic on the back.

Would it work? Has it been done? Is it a stupid idea?

Let me know!