binding in cua--rectangle-keymap using cua--self-insert-char-p
to handle all global self inserting characters in rectangle mode.
(define-key cua--rectangle-keymap [remap self-insert-command] 'cua-insert-char-rectangle)
(define-key cua--rectangle-keymap [remap self-insert-iso] 'cua-insert-char-rectangle)
+ ;; Catch self-inserting characters which are "stolen" by other modes
+ (define-key cua--rectangle-keymap [t]
+ '(menu-item "sic" cua-insert-char-rectangle :filter cua--self-insert-char-p))
+
(define-key cua--rectangle-keymap "\r" 'cua-rotate-rectangle)
(define-key cua--rectangle-keymap "\t" 'cua-indent-rectangle)