> Are there any plans for a space based VLBI; not easy when you consider the utterly huge amounts of information they have to transfer, a radio telescope in a L5 would be a start.
There is space-based VLBI at lower radio frequencies, with the "Radio Astron" project[0]. That effort works at frequencies which are roughly a factor of ~10 lower than that of the EHT. I'm not aware of any plans for millimeter Space VLBI, but the higher frequency would require higher data rates.