Well, we got two baby Dums kept on aspen with nothing but UTHs. Personally, I've been using UTHs for over a decade with no issues. And only recently I've had to use a rheostat for one large UTH that gets a little too hot.

However, a good bulb, as long as it reaches the proper temps during the day, should work fine.

According to most of the literature Ive dug up on Dums, yeah, they're almost strictly terrestrial/fossorial and they rarely climb. So likewise, they do enjoy burrowing, but a couple good hides should be sufficient to make them feel comfortable.