The default behaviour of a timeline group that is loaded to time is that it will fire all MIDI and OSC cues in the timeline group which precede the load time, all at once, when the group is started.
While this makes sense for the majority of situations e.g.making sure a MIDI PC controlled mixer is in the correct state, sometimes it's not what you want.
Here's a solution I made for a user controlling robots with OSC, which presumably would have got their articulated parts in a tangle if responding to lots of instructions, that were normally spaced across a long timeframe, simultaneously
If you put this in a script cue with ⇧Space to trigger, you would have the option of either triggering historic OSC/MIDI cues as per QLab's normal behaviour with space, or only future OSC/MIDI cues with ⇧Space
tell application id "com.figure53.QLab.4"
set osc output enabled of overrides to false
set midi output enabled of overrides to false
tell front workspace to go
set osc output enabled of overrides to true
set midi output enabled of overrides to true
set overrides visibility of overrides to false
end tell
You can also use any of these in the script to use this behaviour with other MIDI message types and Art-Net.