I think they visited him more than the post suggest, they did help him when he nearly fainted a few days ago. They might be bringing him food and he's not tweeting about it. Then again, Kevin doesn't move much so he could be using the few moving times a day to make sure he's walking like the doctor asks, an efficient use of lazy.
Kevin had one of his UK ticket paid for by the internet. Like, he wistfully tweeted an ebeg and someone paid for it. He had another trip planned too so he got a preplanned one he paid for and an ebeg trip he didn't. With moving, I don't think Penny could afford to be away from his dirt farm. This is Kevin going to visit his polycule friends in UK, who will then try to have sex with him and he'll half heartedly suck dick.
Anyway, my point is that I think the polycule is like a weird family that hasn't slept sith each other since their genitals were cut off. We have Penny and Kevin talking about sex they had until Penny fully embraced asexuality with his ball snip (apparently he used to BDSM with the two men, eww), and Kevin obviously had his falsegina attempted. Kevin and Jen can't support themselves financially without Penny (who fails to support himself too), Penny can't support himself ego-wise without other people in his house to baby (the irony of him leaving both his previous wife and kids is not lost on me). There's some love, but your observation of it being misjointed and more like a bunch of nerds huddling together for support is pretty spot on. Hopefully there's rituals and routines they do that affirm love, but it's the kind a loose family would do rather than a group of lovers. Penny being a shit mom and dad to them is one.