Question: MidiOutput::sendBlockOfMessages and time value

MidiOutput::sendBlockOfMessages requires specifying a time, millisecondCounterToStartAt, which “must be in the future”, at which the block of messages should be sent. But how much in the future should it be? I want the midi messages to be sent as soon as possible.

Using Time::getMillisecondCounter() directly seems to work fine, although it is not exactly in the future. In fact, even values in the past seem to work. In my crude tests Time::getMillisecondCounter() - 200 lets most notes be sent correctly (more than that and things get funky).

So what’s the deal? Should I add a few milliseconds to make sure that things work reliably in all situations? And how much exactly? Or desn’t this matter and is using Time::getMillisecondCounter() fine?

And also: why exactly is Time::getMillisecondCounter recommended and not Time::getMillisecondCounterHiRes?