You & your partners did a good job of researching before the purchase of those cans. I own three TBAC 30 cal cans, and have one of their 22TD cans in 'jail' awaiting the receiving of a tax stamp for it. My 1st TBAC was a 30BA, and compared to the AAC SCAR-H that preceded it (and which was later traded for a SF SOCOM 762), use of the 30BA on several of my custom rifles resulted in increased accuracy, and only minor POI shift compared to shooting without it. I've yet to have used any of the three TBACs on any rifle and seen any decrease in accuracy - it's always been at least as good as it was w/o a can attached. As far as there being any advantage to using a direct attachment can vs. one that uses a brake/mount, I'm highly skeptical of that opinion, based on personal experience with these three TBAC cans. The BA was great, but I always thought the BA mount/brake was really - well - fugly, so when they announced their CB series, I ordered a 30CB9, which has been a great can. TBAC announced the release of their Ultra titanium cans just after I got the stamp for the 30CB9, so I bought an Ultra 7. The POI shift with the Ultra 7 is very minor compared to using one of the heavier 9" cans, and it's a bit more quiet than either of them. The 30BA had turned into a bit of a 'safe queen' after I got the Ultra 7, as I'd changed out most of the 'fugly' BA mounts for CB brake/mounts, so when TBAC announced their re-core program - where an owner could send in an older can to have the previous mount & baffle stack removed & replaced by the new CB Ultra baffle stack - I decided to send the old 30BA in & essentially have it converted into an Ultra 9. That took a couple of weeks, and cost almost $900, but it was money well-spent, and now the good old 30CB9 is the safe queen of the lot. With the CB brake/mounts, I can shoot a group at 600 with any of my rifles, remove the can to let it cool while I'm downrange painting steel, then put it back on, shoot another group, and not see even the slightest POI shift compared to the 1st group. So, IMHO, there's no advantage to going direct mount, in fact, there are more liabilities - like, what are you going to do if you get a direct mount can cross-threaded on a barrel? And what about wear & tear on muzzle threads from continually mounting & removing a can? Buy a brake/mount for each bbl you're going to shoot the can on, and forget about screwing up bbl threads.
I've bought a couple of TAB Gear suppressor covers, and had good results with them, although they begin to slide off more easily as they age. Went with Armageddon Gear covers on the Ultra 7 & re-cored Ultra 9, and have been very pleased with them. Not only do these covers make it possible to remove a can while it's still too hot to touch, it reduces the mirage produced by the heat coming off the can.
I've heard nothing but good things about the Dead Air Sandman cans, but have no personal experience with them. Enjoy!