I particularly enjoy thermalling in clouds and would never stay in a 5-knot thermal until it becomes 1 knot. Your Figure 6 green line is great, but here’s a suggestion (the dashed line) of a slight improvement based on what I’ve seen climbing in clouds:
Note this lift only applies IF you’re still in the thermal. Obviously if you wander at random inside the cloud you’ll get weaker lift or none, so that is challenged in the current sim with the very broad areas of lift. But with sensibly shaped clouds (i.e. Cu’s) it is normal to be able to climb up inside the cloud and emerge with a towering landscape beneath you, and you’re certainly not waiting for the lift to weaken to 20%.
Thermalling in clouds is a joy, both when you’re in the quiet in the gray, and when you emerge to see the magnificent puffy landscape around you. Unfortunately it’s terrifying the first ten times you do it.
B21