Okay. I've decided I'm getting Charis back into her viv tonight, without the termite mound for now. Still have to decide whether I'm salvaging that, trying to redo the grout completely, or just scrapping the entire thing for now. Either way, it likely wouldn't be ready to go in for quite a while, or won't hold up if I do just stick it in sooner rather than later.
Also reminding myself that even if it's not what I wanted & planned, the added lights, heating, and new branches are all still improvements to what she had. It's still a step forward. It's still good for her.
I think I'm going to look at using some small plastic containers to do essentially what I had been planning, stacked multiple hides that allow for more choices, more use of the viv height, and maybe more substrate choices.
I do still have a ton of Styrofoam board too, so maybe I'll just do something simpler with all of that. It'll be okay if I do something else for now and revisit the termite mound idea with her next viv, giving myself more time & remembering what I've learned and what Heather wrote up when it comes to the grout.