I just realized that 0.5.10 was release for Nxt and there is this note:

Progress Report: The refactoring of 0.6.0 is going well. The Nxt project now consists of 86 java files instead of 1. I will proceed to work on persisting blocks and transactions in a database some time next week. I do not plan to release 0.6.0 until absolutely necessary, because it does not contain any new user visible features and at this point is likely less stable than the 0.5.x series. Urgent bugfixes and new API's, if needed, will still be added to 0.5.x. Any Nxt clone projects that have been eagerly awaiting the 0.6.x series, so that they can benefit from my refactoring work for free, will have to continue waiting, while we make progress.

Should we wait for the refactoring to be done for the clone?

We've already refactored the decompiled stuff ourselves.

Would you like to trade refactorings then?