Damn digging maroons....
Can't say about the cap melting, but I turkey baste whenever I think of it, just because NOTHING like sand all over it.
You could try a piece of eggcrate below her lair.....you can remove this when company comes.... or not....I don't bother anymore..
I found she dug a lot less when she had a solid base of rock below her anemone, but, of course, I had to move everything around.......
OTOH, xenia stinks....man, does that stuff reek....
I have dreams about that smell man..... :P