nostr:npub1l3gpk6vrudg8r67swqlex5alv9ch59s4lw46kk6hekuxe2n3aczsyqvu48 

Sorry, disagree. Read-only means "read only"...not write/modify.  I've run into this situation as well, and I get it's irritating.  So maybe an option to "allow modify" and only allow "save as..." (as usual), but nah, if I open something as read-only it should only be readable.