Ha, finally we get it. I am very happy for you.
---> uos uses RTL events to pause/resume a thread (the player).
If you set uos_SetGlobalEvent to true, all the players already created will use only one pause-event, the same for all players.( otherwise a particular pause-event is a assigned for each player).
So, with uos_SetGlobalEvent(true), if you pause some of players, when you use uos_replay (that will use the global event), all the paused players will resume, all together, at the same moment without any delay.
---> This for start a player, no free it at end and pause it just after play.
Use this if you need a perfect synchro: first start-paused player then...
---> When all the players are start-paused, use uos_Replay to play the paused players.
If uos_SetGlobalEvent was set to true, you need to uos_Replay only one player, all other start-paused players will play synchro.