I have no experience in isolation games, so I tried a couple of them with Big_Small island maps (on Emperor) but I haven't really gotten the timings for Astro bulb/tech strategy right yet.
Seems to me that after worker techs and BW you have to go writing, then go priesthood to Oracle CoL, and have a GS ready around that time to bulb Philo as well. That should cover the GP generation, but so far either my tech rate was a bit slow or I got only very few cities by the time astro comes. I think after writing you have to go alpha to build research; I tried going math first (to chop Oracle more efficiently) but now I think alpha is more urgent at that point. After that, it is tempting to build temples, maybe lighthouses, maybe even some forges, or some extra cities, but I'm not sure they pay back in time for a good Astronomy date...
I'll need to experiment a bit more before I try this BOTM.