I traced the low level problem down to the 7135. Swapping out the single 7135 for the low channel fixed the problem, so we suspect the batch of 7135's has this issue, even though they have the markings of the "better", correct 7135's. There's history here on 7135 issues. Some could not perform well at low PWM's, but in the past they had different marking so were easy to identify. It's really not a significant issue but does reduce the 150 ramping entries down to ~130. But at least starting at 20 or so looks like it does as well as a good 7135 at level 1.
Raptor Claw is the good one, Sailboat are the not so good ones, see pic here: https://budgetlightforum.com/t/-/44540.
We've had trouble finding the good Raptor Claw ones in the past, Lexel post here: https://budgetlightforum.com/t/-/41018/1484
It's strange, but I believe Lexel came across Raptor Claw marked 7135's that did not perform well.