@maciejireland,
Unfortunately we still don't know when the official version of the software will be available. It depends on the errors which can be found during the Beta version. Hopefully, all the possible bugs can be quickly and easily found, so everyone can enjoy the One UI 3.0. Until then, we recommend you to send suggestions on how to improve the software (any suggestions are welcome:)), or to inform us about any errors you find during your Beta experience, so we can swiftly get rid of them :). Have a nice day!
