I have observed the things you mentioned and experience frequent system crashes now.
Hey kublai,
Unfortunately I'm not too well-versed in this regard so I couldn't help you, sorry. Shortly after Nanquitas posted (right after mine) a link to a working plugin, but I'm not sure if it has anything to do with your issue. The best thing I could think of is re-updating Rosalina to the latest version, running the DS, then rebooting it and install the boot.firm for the plugin. Furthermore, and I forgot which error code it was exactly, but I think the crashes can be resolved by holding select on boot and turning off arm11 exception handler on one of the settings. Or alternatively you could contact Nanquitas on the plugin release thread.
Hope your issues get solved.