He's a little surprised, now that he's thinking about it, that she's not more weirded out by the metaphysical implications of what he said.
...on the other hand, she's talking to an otherworlder right now, so maybe she's just figuring that Rekka has had alien portals of its own.
Hmm. She's clearly not distressed about thinking her existence is time-limited, and they were already in the middle of something, so he supposes he will add it to the queue for when they're done with the current conversation.
He can infodump about historical clothing for quite a while, if she's interested.
At one point, he mentions that with some materials and hand tools he could show her how to build a spinning wheel. This is only partly because it's really cool, and partly because the poor woman must be in desperate need of some technological-bootstrapping training, if she's spent this whole time thinking that this is her only life.
...how many people have departed this world since he arrived, and how many of them knew they were dying, such that they could have at least crammed the basics
...yeah, he really does need to look into actively getting the word out on this, huh. He's not quite sure where to start. Maybe he'll start by asking his contact at the Limited Written Sources archive, who has probably read Minaiyu's translation of the encyclopedia article on walk-ins.
(He sure does keep noticing tasks that are more urgent than providing the Thomassians with information about Rekkan PPE, for comparison with their own tech. He hopes things settle down enough soon that he can get around to uploading that history-of-rubber book.)