I was in the same boat I have had one for years. Leaks everywhere burns fuel like It's free. I put baffle in it and lined the bottom with ceramic briquettes and used a pan of water, it helped but what a pain to keep temps up. I even made a little fire basket that was a big improvement. I think a welding blanket would be a big help.
This is why I now love my UDS but I do see your point about temp spikes when opening the lid on a UDS, but they seem to settle down pretty quick.