this is online and this is free. And the topic list is very interesting and there is a section on vestibular migraine.
The schedule is here
As i was skimming through the FAQs i saw that there is a section on Vestibular migraine (https://www.migraineworldsummit.com/support/)
PS: James, I know you don’t subscribe to the Migraine Causality theory but i think even if we can get one valuable nugget out of the many presentations which will help us, i will take it.