Well, as of yet the temporary ban hasn't officially taken effect, and hopefully it never will and hopefully if it does it will end there. Some of those alternatives may be more prone to severe reactions like the JWH variants prompting the ban, so look out for new legislation sooner or later anyway.
What is your favorite non-banned jwh bonsai fertilizer?
Some are going for AM 2201. Some are into JWH-122. Some prefer JWH-210 or JWH-250, or even RCS-4/8 & SR-19.
Some like JWH-081 and there's even new ones that are even less researched. A new one one the market is JWH-203. There are more than 400 so there's no telling how many may come to market or how many may lead to severe reactions or harmful long term side effects.