The biggest problem with this is that it means the shred which does
the load gets lost in time. It is out of sync because the load time
couldn't be predicted, so you have to do extra stuff to resync it. It
seems better to stay deterministic and just encourage preloading.
I agree that this event would come at a time that wouldn't be deterministic from ChucK's perspective but I'd prefer to have a shred that resumes running as soon as it's useful again over a shred that sends deterministically timed instructions to a soundfont that isn't yet loaded. I imagine we'd only use such a event in the case of instructions that wouldn't make sense to send before having finished loading.
As I understand the situation there would be no need for extra stuff in many cases, we'd just place the sync instructions (of whatever nature) after we made sure the font was loaded instead of before. The exception would be shreds that get their start timing implicidly defined by the moment they are sporked or added. in that case; yes, some extra syncing would be needed but isn't this a case of ease of syncing v.s. ease in preventing audio glitches or missed notes?