Hi Brighteyes, I'm sorry to hear your flushes are so horrible, but just wanted to say I know what you mean about feeling the vaso-dilation effect. I didn't start HRT until 3 years after menopause, but during perimenopause when I went months between periods & oestrogen levels were presumably quite high due to infrequent ovulation, the veins in my inner arms used to hurt as if they were being overstretched. I have since had a repeat of this sensation on starting HRT - when oestrogen levels were increasing & again on each change of regime.
As I also have Raynaud's, I'm used to a similarly painful, over-widening sensation during the final phase of an episode when blood rushes back into the vessels in feet, hands & most painfully - inner ears. I believe the pain of migraine involves similar changes. So I'd say it is indeed possible that you're feeling something similar during flushing. Wonder whether you also have either migraine or Raynaud's, as I've often thought these conditions must predispose women to greater problems with vasomotor symptoms at menopause.
I more commonly get a different sensation these days - arms, legs & feet burn as if scrubbed with a scouring pad, but this isn't confined to the blood vessels, it's all over. It's just mildly painful, but definitely more uncomfortable than what I formerly knew as simple flushes. This burning sensation is worse at night & I often feel slightly nauseous with it.
Like you, I also have a skeletal chronic pain condition that disrupts my sleep, so I really feel for you, as anything else on top can be a lot to cope with. I don't think you mention whether you are on HRT, but if not, wonder whether this is an option you might want to try to help alleviate the painful flushes. Sorry I can't help any more. I hope perhaps a different GP might help you get it sorted.