Does it work well on R9 290?
No tested on R290 only on r390. We will be thankful if you send your results
I tested it on R9 290 and 290X, seem to work fine on regular v7.
Are you planning to improve this software somehow or is this the final release?
For the release of the final version is still far away, there are many interesting ideas that are not yet implemented. They will be implemented in future versions. Also, the code will be optimized.