Home Assistant doesn’t “support” miliseconds for a delay, if that’s what you are asking.
what do you mean?
This works
delay:
milliseconds: 300
just asking if this is accepted
delay: “00:00:00:03” or not
Yes, just found out that it is indeed supported. I don’t know if this format 00:00:00:00 works, why don’t you just try it?