I have been looking at the cpu utilization and indeed the vera cpu can make enormous swings and remains at 100% when it handles a string of commands. Encouragingly, it seems like it is running on both threads of the core.
Found a new deeper problem with the vera plus. I managed to reboot it completely attempting to copy files (a lot of them) from it to make a backup through SCP… It seems like it is not just a luup engine issue. Not sure whether I flooded its memory or overheated the CPU just with the sheer amount of file requests. It crashed when transferring very small files which means very high frequency requests coming from the guest computer…