I know what you're going through. After my last post above, I went ahead and painted the Ultima Eco and had a similar result.This is the process I went through:
-Sanded the old paint down to previous barrier coat, washed, washed,washed.
-Re-applied four coats of Interlux
2000/2001 barrier coat.
-Applied one coat of Intelux Bottomcoat as a tie-coat.
-Applied two coats of Ultima Eco exactly following manufacturers guidlines.
-Waited a full week to cure before launching.
What I observed was that the Eco took forever to harden up and even with a week of drying in warm temps, it still did not harden up the way I thought is should ( I could press a fingertip and leave a print). With the boatlift, we used waxed paper and fresh carpet to pad the slings and still had paint pull a bit, but not too terrible.
It has now been 4 months since launch and since it has been extremely hot out, we haven't been using the boat as often as we normally do. The Eco paint does get a layer of very slick soft growth but so far, no hard growth at all. I would suspect that if we were to be using the boat more frequently, the soft growth would slough off, some of which was occuring last weekend after sailing for several hours and I dove under to check the condition. The jury is still out on the long term effect of this paint.
I knew I was a guinnea pig with this paint, but I like the idea behind it.
My previous paints have been both ablatives and hard paint like Trinidad, but Trinidad had gotten so expensive, plus it builds up. I have had good luck with Super Ship Bottom, but you have to mail order this paint.