Cable sheath damaged, cable core filling and conductor insulation intact

One should not ask if one does not like the answer and you know better anyway, even without being an expert.

Maybe one should simply not contribute at all when the questioner has explicitly forbidden such pointless posts in advance. And honestly - our electrician is a professional, and he clearly sees it differently in terms of content than you, who obviously invented the profession. So just teach people who ask for it with things you really know - and that no expert sees differently from you. But if you like, and it helps your soul that is not often enough recognized by this world, you can gladly spam this thread from here on with unsolicited and factually incorrect lectures, my problem is solved anyway without your help! Let the world finally see and appreciate you and your wisdom - what else do you want to explain to us?

If neither the RCD nor the circuit breaker trips, heat shrink tubing is fine. If you don't have an RCD before, then one should consider it. Of course, purely a private opinion without liability or anything else.