Viv size?

[PitOnTheProwl]

Is a 20 gallon/2ft vivarium ok for a 4 week old BP (at the moment he is 85g and two weeks old) as long as I cram it with plants and decorations to help him feel secure?

The thing is, I'm planning in using a ceramic heat emitter and am worried about it melting the plastic.
So far he has had no feeding struggles with the breeder (and will have had more than 5 feeds when I get him), and I'm not sure on how to maintain a correct ambient heat gradient in a tub of that size...
If I do get a 20 gallon and fill it with enough things, is there a chance he will still feel secure?

Someone isn't telling the truth or is misunderstanding.......