Your right @Perrry, the distance between them is a big problem now. I was just replying to Arni’s question about clouds drifting with the wind. Problem with the distance between thermals is that in mountains they are over the peaks, but in flat country they are randomly spread around. But the rule of thumb is that they are around 3 times the distance apart compared to their height.
As for the colder air bit: I am finding sink as well as lift in the sim in live weather.