Hi Wim, not sure how much help I can be on either of these type Epis needing ID. The first one is striking, I've heard of a deep purple petaled form of E. epsteinii, although sepals don't look wide enough, and they're pink instead of white. I had the form with the dark flesh pink-brown colored petals, and the hallmark extra broad and rounded pure white sepals; looks very different than what you show. So, I don't know what it is.
On the second one, I thought it looked like E. sutchenense, but then I see you mentioned "clumper", and sutchenense is a runner. Here are two photos to show the flowers look similar. Maybe as you say, your not-Madame Butterfly is a hybrid.
E. sutchenense in my garden last week:
