1. Any refinement can be transferred to os, the only question is the time that needs to be spent on it. If the question is put like this: is there a list of improvements that have not been transferred to os, then no - there is no such list. You can see for yourself whether it is in os for any revision of interest
2.
https://1b.app/ru/partner/onebox-corp/ write to the partner, you will be told the cost. As far as I know, the cost is only in the purchase of keys, the transfer itself is free or may cost a couple of hours depending on the project. But here I can’t say for sure because I don’t know all the nuances