Charles, rumors I have heard is there was a Canadian who wrote a computer program years ago to address the factors you mention. He may have been from the BC area.

For the V2 I have found that I think in terms of dry (about 7.4 lbs/ft2), 8, 9, 10, and full (11). Rough approximation in flat lands without much streeting is less than 2 knots, 2, 3, 4 and 5 or more match the above wingloadings.

If you have ridges or streets you can carry more water in weak conditions because you are cruising more of the time.

Most pilots I know start heavy and dump some if they can’t climb. I often load to the expected climb and conditions so I know my gliders weight and cg. CG Is the hard part to control when dumping. I think many racing pilots fly too heavy in weaker conditions.