And then Phix asks:
"So, what could be done to portals to make them less vulnerable to small invisible monster spies?"
"Well," says Prime, present for obvious reasons, "there are a few methods we could go with. Something that gives off a magical signal's the most obvious, but hardly the only one. I could key it to let only us through, no one else, or I could have it let people in who are holding certain unique items, or only open from the side of Pantheon so you'd have to mirror ahead to have someone else open it."
"But! On the bright side," chimes in Cypress, who is here for the same reason Prime is, "If we are really specific about what we put in the microchip, to the point where there is nothing else like it in all of the multiverse, scrying each other becomes a breeze."
"...Medallion because dragon, Inferno because if somebody found it they could bring daeva, Chamomile because questionably okay mages are aware of the plane, Hex because spellbinders could be trouble and we have to be especially careful not to kill them if they show up since familiars, yours last?"