Hey, yeah I think this problem has been here for a while ?
You can either do a sequence pool, and you pick an available sequence device in the pool whenever you need to play on a single instigator. (see this Snippet By Twin)
Or you can also swap the players team to another one and set the sequencer Visibility to Instigator's Team. I guess one could instantly swap their team to their original team right after playing the sequence? (maybe even on the same frame, needs testing though)