My opinion: Solo both portals at the same time. Maybe send an extra in for a few seconds to fire off a few rockets then leave if the two soloers aren't 100% competent at soloing. This is easily the quickest most efficient method IMO.
These are the 3 main strategies ive seen used with only mild variations, so if you use a method similar to one of the above vote for that one.
-
I find the method that works best, is that someone (usually me) solos the first one, comes out and drops the relic for someone, then we move over to the second one and same person solos the second one while the relic stays outside to help because i can kill the gatekeeper and get to the relic faster than i go blind. I then wait in there to cleanse myself, then run out, cleanse myself again and everybody gets to conflux.