I cleared another sdcard and used rufus to install the K version. Kodi appeared on the screen so the bootup indeed went well.
The remote didn't work though. Did the procedure again but this time copied the renamed mxq pro device tree to sdcard. Stripes on the screen again. As I need this remote, I think I'll stay with the J version for now.
For me, even a clean installation of K does not work (Mini MX 2G). It bombs out at the LE logo, same as when I upgrade to J from K. Just thought I'd mention it as a few people here are saying that a clean install kinda works. It is connected to a 4K TV, which may be significant. I don't have a different TV to try it on.