You may all remember when I wrote about Hulsanpes, I provisionally excluded it from the enantiornithines because metatarsal IV is not reduced. I did this because, as I said, this has only been confirmed in American species and Concornis. Now I have Hou's paper on Chinese fossil birds, so I can properly compare Hulsanpes with Asian enantiornithines. It turns out my suspisions were warrented, as not all enantiornithines have reduced fourth metatarsals, Cathayornis? caudatus, Iberomesornis, Largirostrisornis and Sinornis being the exceptions. Iberomesornis also has an unfused metatarsus, like Hulsanpes, while the other three species have proximally fused metatarsi like other enntiornithines. Unfortunately, further comparison is difficult as the pedes of Iberomesornis and Sinornis briefly described, while those of Cathayornis? caudatus and Largirostrornis are described in Chinese. Largirostrornis appears to have a ginglymoideal articulation on metatarsal II however, which is similar to Hulsanpes, Patagopteryx and Vorona, but unlike confuciusornithids. Also up for consideration as a non-ornithurine member of the Yandangornis + Pygostylia group (and thus comparable to Hulsanpes) is Jibeinia, which has a proximally fused metatarsus that is similar to enantiornithines. So the revised placement of Hulsanpes should be a non-ornithurine member of the Yandangornis + Pygostylia clade, which includes the possibility of enantiornithine or "jibeiniid" affinity.
Also, here are the pedal proportions of Jibeinia (prepared for James Farlow) if anyone wants them. The lengths given are percentage of metatarsal III length, which is 16.3 mm, without the distal tarsals. Unguals are measured in a straight line from most proximal to most distal point. There is no fifth metatarsal preserved. These are all from the right pes.
Finally, Fredericus Ruhe alerted me to the fact that the unnamed Mongolian enantiornithine I mentioned in "Details on Jibeinia" as being described by Dong (1993) is actually Otogornis.