Kilamanjaro is 5895 metres, and EBC is 5380 metres.
You're correct that in the study, the Kilamanjaro climbers (n=7), most of them came back with normal brain scans. That is definitely encouraging.
Also, I have heard that Kilamanjaro is tougher than EBC, due partly to the rate ascent and people pushing themselves too aggressively - if I was to do EBC, I'm happy to take it slower, to avoid AMS. I'll probably be taking diamox, but I don't know if that makes a difference here.
(I did the Inca Trail to Macchu Picchu with a group, fairly aggressive pace, but it's considerably lower - although I just Googled and apparently the highest point on the trail is 4215 metres, so maybe not that different).
There may be hope yet...haha.
How did you find your trek via Lobuche East? Any ill effects? And you found it easier than Kilimanjaro?