Scottishcammy I just remember there were issues when I was trying to do that before, I think it was eco kept switching itself off, but my memory is poor so couldn't recall exactly what it was
Ah, okay, yes...
One thing to note that, while timed discharge has always been described as holding power until needed, in practise, on most inverters, it used to actually behave as "timed export, but without turning off the eco flag". That has now all changed. Timed discharge now actually configures the pause timer to pause discharge when it's not wanted. Timed export shouldn't turn off the eco flag, but on gen-1 inverters (except maybe on the new "fast response firmware) it is actually necessary to turn off eco flag to actually achieve export.
I'd still double-check that configuring a timed-export doesn't turn off the eco flag, though...