UKV Thermal height often 0

[tomA27]

I am new to Windy but it seems to me that the UKV Thermal height prediction differs greatly from other models despite only slightly differing soundings. In particular, it seems to be zero over large areas where other models have reasonable predictions. Can anyone offer an explanation?
Also, it would be great to have Cu cloudbase and thermal updraft velocity easily available in the same screen.
Given a fix to these things, I would sign up for premium tomorrow.