Soft selection for pinning Cloth Bind

[jackasssero]

Had another look at this as I currently need to do something similar:

The cleanest way seems to be to do in "post", at least as far as I can tell.
You'll  want to deactivate your object bound particles (just like you did) to avoid overstretching at the cloth transitions.
You can omit the deactivation and use softer bounding methods and values, too, and stack them if need be to get a stronger, but not infinitely strong bind, and that might be enough in this case like betamax demonstrated, but the cloth bind will continue to mess with those particles. Which is good in this instance, as it hides the transition, but not always.

So for a precise transition, cache your cloth sim with a hard transition (deactivated particles) and then use a tyConform modifier to blend to your original animated mesh by vertex ID (basically a morph between animated meshes), masked by the map of your choosing (tySelect below and "Use vertex selection" in tyConform).

I ran some tests based on betamax and your suggestions and also tried out a bunch of my own experiments. I wouldn’t say this feels like the smooth workflow I was hoping for, but it really helped a lot and opened up some new ways of thinking. Thanks a lot for checking it out, I’ll keep testing the stuff you mentioned.

And if you ever think of something else, or have a scene example to share I'd really appreciate it!