because when I saw JLM's Creature, he moved me far more at the end with his tenderness towards Victor.

I think it may have been that Cumberbatch's Victor never evinced any tenderness toward the creature, so that the flash between them couldn't happen.

I haven't seen anything else Nick Dear's written, but I'm willing to believe somewhat ham-handed dialogue is a common flaw of his. I found the audio landscape beautiful and would have loved to experience it in person. I definitely envy your having seen these performances live.