Is this metal rocket stove a good product?

We're looking at the metal rocket stove these folks sell: https://www.rocketheater.com/

Does anyone have any experience with this? Are there any obvious warning signs that there could be trouble with it?

Uncle Mud aka Chris McClellan has done a review of the Liberator rocket stove. He has many videos that you may want to check out on Permies.
Just type "LIberator" in the RMH forum and you'll get most of his reviews.

Uncle-Mud-Liberator-Rocket-Mass

That Liberator stove looks good. I am trying a smaller stove for small spaces. It’s not UL listed.  Not sure how big you need.
https://www.shtfandgo.com/product/bullet-proof-rpg-rocket-stove-and-heater/