The REPL interaction mode you are looking for is probably met by ielm (Inferior Emacs Lisp mode).
Here's the start of a solution†:
Open ielm-mode with M-x ielm.
Advise ielm-eval-input to wrap the expressions with edebug-eval-expression:
(defun my/ielm-edebug-eval-input (orig-func input-string &rest args)
"Wrapper function for evaluating expressions ...
This behaviour is controlled by the eval-expression-print-maximum-character variable.
eval-expression-print-maximum-character is a variable defined in `simple.el'.
Its value is 2305843009213693951
Original value was 127
Probably introduced at or before Emacs version 26.1.
The largest integer that will be displayed as a character.