Agree with you that this is most likely a Hill Blue Flycatcher. Not because of the lack of irridescence on the shoulder which is because this is a First Winter bird which haven't complete it's contour feather moult, but the orange wedge is very broad around the throat and seems to almost reach the base of lower mandible.
Orange wedge pattern can be higly variable from an individual to another and variation limits are not well documented, but I doubt glaucicommans can show such a throat pattern.
This bird appears also very bulky body which is also pro Hill blue to me.
Contact call between hainanus, banyumas and glaucicommans are very similar, so not a usefull ID tool...
Both glaucicommans and banyumas are often see on perch close to the ground, so also not very usefull...
All the best,
Jonathan
