Playing trumpet is alwyas more desireable than just working on it, IMHO.
FWIW, however, I do think learning how to lip buzz as close to the way you play as possible has merit, but it does take patience. I wouldn't spend more than 10 minutes a day on that right now. Include lots of lip fluttering to keep them from becoming spent during this part of your warm up. It might take quite a long time to master lip buzzing and applying it to the horn. It did for me. When I first tried it I abandoned it as nonsense after a few weeks. Then I hooked up with Bobby Shew. After trying it again at his suggestion I got the hang of it. I just needed to rest more and not overdo the buzzing and I needed to persist in the learning process.
Just some thoughts.