I think the regen power bar pretty much scales to the mode it's either put in by you, or forced in due to external circumstances, ie a high battery, rough terrain etc forced it to a lower setting.
So lets say level 1 is 5 kw max regen Lv 4 is 30 kw max.
even though you may have set it to 4, the battery is high, or it auto scaled down and is temporarily at lv 1, and you are putting 5 kw into the battery. You may not see it but you sure can feel it's only 5 ie mild regen vs 30 half your BW bring pushed to the windshield. now what YOU have it set at, 4, that 5kw that's only like 20 percent of the full scale which is what you expect to see, given YOU put it on Lv 4, but where it currently is set at (temporary 1), that's full scale, so it shows that.
I wouldn't worry too much about that little part of it.
Aaron