So I’m guessing that you’re trying to find the optimal settings that will give you the fastest setup/load time? What is your setup? Are you accessing EMS directly through a player such as ffplay?
The xxxBuffer variables that you are setting are used to minimize jitter and not setup time (although I think at some point it affects it indirectly).
Regarding VOD and pseudoVOD, I’m thinking that since the file is already loaded on EMS and you would just access it directly using its local stream name, it is played almost instantaneously. As opposed to VOD access where EMS have to load the file first and then stream it to the client.