I'm not sure what you mean by "does ot workk in 85%", Carve seemed to work good everywhere I went in Taos. On my trip it was icy with no recent snow so off piste was poor conditions except for the very top which was fun. If I had skiied more off piste I don't forsee any issues using Carve as I think it still gives some useful feedback (even if less helpful than on piste) but I'll have to test that more.
I never said I was restricted to groomers, or that I need more time skiing off piste. I think previously I could do 100 runs off piste and there just wasnt much improvement happening from run #1 to #100. Sure expert lessons would probably have been best but with my very unpredictible skiing schedules and budget limits that hasn't always been possible. I think Carve helped in those 4 days more than any period in decades. I'm not expecting it to be a complete solution to all my skiing progressions and yes will need to continue to explore all types of terrains/conditions.
CArv only provide meaningful data on your skiing while you are "carving" on the groomer. The data it provides when you are off piste is meaningless. It's not designed to evaluate your skiing off piste.
I ski Taos literally everyday from mid-January till the end of the season. I am very familiar with the terrain there. I would say more that 85% of the terrain is off piste. We seldom skied groomers other than a warm up run or moving to a specific area/lift.
Well, about the poor condition off piste, That is when your skiing can take a quantum leap.
To paraphrase Bob Barnes, "There is good snow and thee is good for you snow. Ski the good for you snow often enough, it all become good snow."