Here's a patch that implements the changes described in my previous
message. It defaults to the current behaviour.

Andrea

  --- electric--v28.1.el 2022-08-02 14:41:09.578483586 +0200
  +++ electric--modified.el 2022-08-02 14:47:17.712875776 +0200
  @@ -534,6 +534,11 @@
     :version "26.1"
     :type 'boolean :safe #'booleanp :group 'electricity)

  +(defcustom electric-quote-replace-consecutive t
  +  "Non-nil means to replace two consecutive electric single quotes
  +with the corresponding (opening or closing) double quote."
  +  :type 'boolean :safe #'booleanp :group 'electricity)
  +
   (defvar electric-quote-inhibit-functions ()
     "List of functions that should inhibit electric quoting.
   When the variable `electric-quote-mode' is non-nil, Emacs will
  @@ -586,7 +591,8 @@
                                 (memq (char-syntax (char-before))
                                       '(?\s ?\())))
                           (setq backtick ?\')))
  -               (cond ((search-backward (string q< backtick) (- (point)
2) t)
  +               (cond ((and electric-quote-replace-consecutive
  +                           (search-backward (string q< backtick) (-
(point) 2) t))
                         (replace-match (string q<<))
                         (when (and electric-pair-mode
                                    (eq (cdr-safe
  @@ -600,7 +606,8 @@
                        ((search-backward "\"" (1- (point)) t)
                         (replace-match (string q<<))
                         (setq last-command-event q<<)))
  -             (cond ((search-backward (string q> ?') (- (point) 2) t)
  +             (cond ((and electric-quote-replace-consecutive
  +                         (search-backward (string q> ?') (- (point) 2)
t))
                       (replace-match (string q>>))
                       (setq last-command-event q>>))
                      ((search-backward "'" (1- (point)) t)