I think it should work ok. I haven’t used so different versions myself, but i have seen reports in the forums about using even 2.5.8 and newest versions together. I think the most affected part would be file transfer. Btw, file transfer is a bit broken in 2.8 series. So, if you need it, you are better with 2.7 versions. https://github.com/igniterealtime/Spark/releases