Hi early bird2, (nice name
thanks and yes, degree of pre filling is very important:
In light wind as much as possible,
in strong wind with obstacles in lee sometimes better less.
But you can always create distance by (especially in light wind) swimming towards luv, to get more time for your launching maneuver. And the ability of the kite to release water via drainage is also very important. As I have seen you have an Ozone Hyperlink I will write about possible improvements for Ozone kites into this topic:
The conclusion is, even an Ozone Chrono V1 is able to drift launch, but it may take some improvments on the canopy and will take more time, wind and space, as you drift longer distance.