Hi. The files for the S9+ are finally available for download and flashing. The procedure is the same as for the S10 and may be consulted here.
I do not believe that the final release will take much longer as there are no newer builds yet despite the fact that the beta was released a week ago (sorry for not posting earlier but the files were up). Hopefully January.
I am still waiting for Note9 files.
Have a nice day!