I came across something interesting when I forgot to take a part out of the IPA bath. I had to go out of town and left it the 99% IPA bath for 6 days. When I got back, I removed the part. The part was noticeably more flexible and has maintained that flexibility for 3 weeks now. I doubt that this is long term. However, it is interesting. I am no chemist or chemical engineer but perhaps it is the IPA molecules infusing between the cured resin?
Yes you are on the way. But the IPA will diffuse again and the item would be cured. If you observe IPA-Time and curedprocess you will find the best timing for accurate pieces. The answer for the best result has to do with the volume - surface - time and postcureprocess. You are on the right way.