Poly thinset as scratch coat in plaster wall?

I'm rebuilding a section of wall where I tore out a long-ago decommissioned interior chimney. 1890 house, walls are wood lath and horsehair plaster. I've already torn out a bunch of lath and reframed where Im going to be putting up drywall.

Theres a few areas where it makes more sense to me to just repair the plaster than completely tear out, roughly 4 or 5 sq/ft total.

Im finding lots of conflicting info about what to use for this. Right now Im thinking: thoroughly wet the lath in preparation, then use polymer modified thinset for the scratch coat. Then maybe a mix of poly thinset and hotmud for the "brown" coat. Then some general purpose mud (I typically use plus 3) to feather it to the new drywall.

Overall Im pretty good with cement/concrete and drywall, so Im confident that I can make it look good. Im just concerned about how it will hold up over time. Im thinking if I use poly thinset and properly key it into the lath, it should hold up, right?