I've wondered about this too, when they get big into flower, it seems like they would be hard to manage when doing res changes and things.
Mine are still early in veg and what I do is take the lid off and put it on another extra tub I got just for when managing the res. I just sit it right down on the extra tub while I work in the res. It works really well for now but Im worried about when they get bigger and the roots are goin everywhere, maybe it will keep working the same way, only time will tell I supposs
I have two tanks in my Tutorial, both had 4 plants with one plant in each that was a giant 52 to 54 inches tall. After I started 12/12, I quit removing the lid and I just propped up one end and easily worked in the tank. No plant fell ovor or dropped in.