Anything that doesn’t work well that you’ve seen with the Owl extension?
TB is slow overall, mainly due to Defender. OWL also totally Broke last year when TB updated on a point release, fixed by OWL in days.
At some point I somehow got logged out and then was unable to use the OWA login inside TB, because it required some silly JS to run. That meant Owl could no longer fetch e-mail. I contacted them about it, but they did not care and basically shrugged and did not give any advice.
At some point I was able to switch to using OAuth to get my e-mail, without Owl.