I'm also thinking about relocating my spare tire. Because I have a second fuel tank under the bed, Toyota placed the spare tire against the back of the cab behind the driver.
But I would like to add a toolbox into the truck. My old Tacoma had a crossover toolbox and I loved it. I used it all the time and kept a ton of stuff in it - hand tools, utility knife, breaker bar, jack, air compressor, bug spray, sun block, water, soap, TP, clean clothes, work gloves, oil, paper towels, first aid, etc. I could have lived out of that truck if I needed to. It was a great bugout vehicle.
@Hondu moved his spare tire closer to the tailgate and I'm thinking about doing the same thing. This frees up space to mount a toolbox against the back of the cab.
You basically just pull the mount off the back of the cab and mount it on the side of the bed.
What do you guys think?