So…there appears to be a major bug in Search and Destroy in the Black Ops 4 Private Beta.
If you pick Seraph as the specialist, and place down a respawn beacon, you can currently respawn back into the match — even though that is supposed to be restricted in S&D. It may be that the player who placed the tac deploy beacon down can respawn back, although it may not let all of the teammates do so.
Also, be careful! Changing your specialist mid-round will eliminate you for that round.
We’ll update as we learn more..