Thats it. Spread the news. I heard about hissing a little while back and I am spreading it as much as possible too. Its God's gift to us humans who aren't catparceltoung.
I'm not judging the nose thumping and I hope the cage reconstruction works out. That said is it possible she likes the heat lamp? If you gave her a heating pad under a blanket (maybe even some where high up) would she leave your tanks alone?
First thing's first I love the name Nagini *cries in parseltongue* and your snake tank looks pretty awesome!!
Is this a room you're in often? Does she just seem to like "being on top of things"? Maybe she just wants to be near that spot but also wants a high place to survey her territory on. She's a cat after all And a pretty one at that!