Absolutely perfect. Beautiful work.
I have mobility issues and a 15g when wet was a bitch to move, shit spinning her was hard. If you go big expect it to stay where you put it. Would think it would help out somewhat not having to move it. Thats a lot of medium in 16sq ft. Wouldnt a 4x4 tray work? If raised up a bit? Just a thought, good luck!
Super helpful not having to move pots, even without mobility issues. Gardening of any sort can be brutal on one's back if not careful. Does seem like that's a lot of medium in 16 sqft, but its actually not all that bad. Only a little more than 10g per plant since he has 9 in what looks like a 100g pot to me.
As long as the 4x4 tray isn't one of those flimsy hydroponic ones, something along those lines should work just fine.
However, my recommendation will always be something like
this pot here. Only 1ft tall and, so perfect for tents as that 100g pot will fill a 4x4 area perfectly. That pot will fit 6-12 plants (strain dependent) with ease, each plant getting between 8-16 gallons of soil. Fraction of the price of one of those hydro trays too.
Absolute easiest and best way to do things indoors now, IMO. Way less work, so perfect for those with mobility issues, and also perfect for preventing anyone from experiencing mobility issues. Trust me, years worth of playing in dirt and moving pots are can quickly take its toll if one isn't cautious.
This way, instead of top dressing multiple pots, you just top dress the one pot. Also don't have to water a ton of pots either, just the one. Cover it with mulch and you'll be set for a couple years in that set up. Only need to top dress and water. Shouldn't have to empty that pot out for a couple of years or so.
Regards.