Nose rub, yes it is a sore on a nose, like rug burn for people.
Amount of waste...... Well imagine the biggest amount of poop and pee that say 6" frog can produce. Like how much do you imagine? Ok now multiply that by 4-10 lol and if you have 7" giant bullfrog male..... Nope, none of the filters can handle that.
Well you still can use plants, but you gotta hang pots above the ground, with pacman it will work, they just sit there, but if pixie decides to jump.... My boy once managed to jump out of 24" cage....

and if talk tank sizes 12x12x18 tank or similar would work for adult male cranwelli, for females and ornates you wanna go for 18x18 footprint. But while they are little you need even smaller cages.