The size of a spider is determined by the amount of oxygen in the atmosphere. I think you can create superspiders in a tank filled with a shit ton of extra oxygen
But spiders can climb walls- they'd still find a way in (open window, chimney, maybe even dry walls if they're desperate) D:
This just reminded me of the movie 'eight legged freaks'
even with tarantulas you can see that the arboreal ones are much more streamlined... its feasible if you made an environment where a huge spider could survive that it could climb but the heavier ones would be grounded.
Don't give God ideas
FOR THE REST OF ETERNITY
This just reminded me of the movie 'eight legged freaks'