I go to TSM regularly and can vouch for their quarantine procedures. In fact, I'd almost guarantee that their QT protocol for all fish that come through their store is more thorough than 90% of hobbyists on R2R. Their QT/acclimation vats are massive and in addition to observation and medicated periods, they also condition their fish to accept frozen food. They're absolutely anal about making sure every fish they sell has a clean bill of health prior to being offered for sale. I'm always the guy preaching to QT everything no matter what, but TSM is my lone exception to this rule. Whether you decide to QT or not is up to you, but I can say that I fully trust them and that's something I can't about any other vendor I've dealt with in my 19 years in the hobby.
With that being said, an additional observation period never hurts. Personally, I wouldn't proactively treat any fish that I know just went through an entire medicated QT period for two reasons. The chances of them having a disease after a full QT period are very low and the fish was already exposed to an arsenal of meds recently. It's obviously your call on whether to QT or not and I'm literally NEVER the guy saying it's ever ok to skip this phase, but I just had to give my feedback of a great vendor. These guys are definitely one of the rare exceptions in this industry and I'm hoping people continue to support them. Enjoy your new Gem!