Are there any preset functions that will add a solid border around the room descriptions on a room by room basis? Or object descriptions on an object by object basis?

You can do it in the description itself:

<div style="border:solid 2px red; padding:4px">The room is not like anything you have ever seen before.<br>In particular, there's an odd red bit of trim circumnavigating the floor at the base of the walls.</div>

which looks like:

Thanks. Was hoping to be able to just check a box rather than having to do that in the description, but it'll work.