If I were building a repeatable tac driver, the Sadlak scope mount would be my go to mount. It is strong and stable. Its success was built on the back of the Brookfield scope mount designed during the XM25 project back in the late 1980s.
These mounts based on the Brookfield mount, to include SEI mounts were used successfully by the U.S. Military and had no serious short comings. The only scope mounts used in any large numbers with known stability issues was the GG&G scope mount used by the marines and yes these were tack welded to the receiver because they had stability problems, none of the other mounts based on the Brookfield design and including the Brookfield exhibited this problem. There may have been an atypical problem but that was more to do with manufacturing than the design!
While Sadlak would be my first choice, there are several others you may want to consider.
Basset, Arms 18, and our own redneckyankee are others you should look into.
MORE THAN A HOBBY, A PASSION!