Excellent timing, cause I was about to post what I know of these options too.
I ordered a Tapps primary from Evo on February 3 a few days after the stop sale was issued. They told me they needed additional parts to complete the ordered and expected it to be 1 to 2. They indicated they had a lot of orders over that weekend. Yesterday they updated me and said the expected parts this week and next to fulfill the backorders. I'm hoping mine will be here next week, but they could not confirm until the parts arrived.
Also, I contacted STM to get a status on their clutches. I have run them before and had good luck. They indicated that they are still testing and would have one avaliable soon (it would be similar to the Polaris Rage 3 design). He said the process has slowed considerably as their test H2 blew a differential and they had to wait out the repair process. However, one thing he said that sounds like it may further delay the release is that they wanted to hear from Kawasaki on the rationale for current failures. He said they did not want to release their clutch if it was more of an issue with motor or crank (e.g. shaft imbalance or harmonics or heat). So I woukd expect them to be available in the future, but could still be weeks or months out. You woukd have to contact them for more details. Their techs are good guys and helpful to talk with when you need info.