Honestly, you don't even need a replacement for this. It still works....provided you fix it up.
Proof (click to view fullsized image)
Took me a few minutes to convert the code over to new syntax, I converted the thing from using "ent" for both the tripmine model entity and the env_beam entity and made the env_beam entity use "ent2". I also changed the tripmine model over to prop_dynamic_override which may be why the thing can float now.
Also modified the datapack to add in the ent2 data so that the env_beam can actually display properly, and everything works just fine now. I probably could have left it set up with both the prop and beam entity defined as "ent", but that seemed lazy to me.
I'll release my fixed version shortly.