Hey Kenneth,
ok, fair enough!
I usually schedule the V3 job immediately after launching the init w/o data. Anyways, it doesn't really matter (unless you have performance issues on your source systems database)... all the V3 job does is write entries into the delta queue, but those delta's are already available in your tRFC queue (which can get pretty big if you wait a long time before scheduling the V3 job).
Cheers,
Raf