Yes been there done that already, while I have kept BP for 13 years for breeding purposes I have 20+ years experience keeping reptiles (back than that was one or two at the time), I used to rescue iguanas (which are likely the most poorly kept reptile in the industry), so I am familiar with enrichment, tub, bioactive setup,large enclosure etc, it agsin all depends on the species you keep, lizards are very intelligent and greatly benefit from enrichment and bioactive/natural and large setup well at least large enough to accommodate their size.Can I ask you an honest question? Would you keep your animal in the same exact set up if you only had 1 and did not breed? Or would you try and provide more for your 1 reptile? Even though they may not more to eat shed poop and breed?
In about 10 to 15 years when I will retire from breeding the snakes I will keep (handful of BP, and a handful of misc snake species) will remain in tubs it has work for 13 years and will still work than, again the key is that the needs of the species are met.
The geckos I keep will remain in naturalistic environment and I believe both snakes and geckos will have the same quality of life.