I don’t see any reason to wait.
SpamSieve 2.9.13 includes some more changes to make training from Apple Mail faster.
There’s a new Faster Apple Mail Training on Mac OS X 10.9 section of the manual with more information about this.
With recent versions of macOS, the GUI scripting workarounds that some people needed to make Apple Mail faster at moving messages after training them as spam should no longer be necessary. If you are finding that Mail is slow, there is some general troubleshooting information here.