Having searched the forum on solutions on this matter, i can't help to be confused by why dealing with this issue is so time consuming. As I see it Joplin is the kind of software that users can use and focus on writing without distractions having content seemlessly synchronised all to simplify and to save time while at the same time having very advanced features should the user look for them. But for reason I cannot possibly understand it lacks two features I consider basic namely:
Disabling orange "warning" boxes is not currently doable unless you do some complicated CSS (which takes far too much time for average user to grasp), this should be a tick box in the settings or simply have a cross on the orange box itself. They are a warning to the user that something is wrong and thats great, but if the user chooses not to deal with this should they really be punished having their UI "stained" and downright distracting.
Allow users to delete master keys, especially ones that are missing. The only solution I found online is multiple step involving deleting pretty much everything and recovering a back up. On linux this is trivial, on windows just extremely annoying. This wouldn't be that much of an issue if not the fact that this forces orange box warning that can't be removed.