
Well, it has been a long time ( 6 years ) since I did a deep dive into the current state of Hoya taxonomy, but this inspired a fresh look.
Most pertinent and insightful is this three year old paper:
Rodda, Michele, et al. "Phylogenetic studies in the Hoya group (Apocynaceae, Marsdenieae): the position of Anatropanthus and Oreosparte." Willdenowia 50.1 (2020): 119-138.
They do not accept Eriostemma, but do erect (agree with) the new genus Papuahoya. The genus Oreosparte is also supported.
They leave Dischidia intact. The rest of the genus Hoya in the widest sense, is still "problematic".
Also important is the two year old study:
Rodda, Michele, and Matti A. Niissalo. "Plastome evolution and organisation in the Hoya group (Apocynaceae)." Scientific Reports 11.1 (2021): 14520.
They seem to support resurrection of Clemensiella (which may include some of the putative Eriostemma). Their best quote: " Based on our results either Hoya needs to be separated in two genera, Hoya and Clemensiella, or Hoya needs to be more broadly circumscribed to also include species currently in Oreosparte. In this latter scenario Clemensiella, Oreosparte and Clade I (Group 1 and 2) of Hoya may be allocated to subgeneric rank."
A more recent paper by Odago, et al did not shed much new light:
Odago, Wyclif Ochieng, et al. "Analysis of the complete plastomes of 31 Species of Hoya group: Insights into their comparative genomics and phylogenetic relationships." Frontiers in Plant Science 12 (2022): 814833.
Wanntorp, Livia, Katherina Gotthardt, and Alexandra N. Muellner.
The promising sounding paper:
Baltazar, Alcona Mae P., and I. E. Buot. "Controversies on Hoya R. Br. Taxonomy." The Thailand Natural History Museum Journal 13.1 (2019): 59-68.
is nearly useless in my opinion.
So, it would seem some changes in the limits of the genus Hoya are happening, but a Genus Eriostemma is not one of them.