The only thing that needs to happen is for the api to be enabled on kbin.social. Interstellar should work with any kbin/mbin instance that has the api enabled.
I haven't really noticed much of a difference. I figured it was probably worth actually being able to wake the laptop from sleep rather than having to restart it every time.
So to check what suspend states your laptop supports run cat /sys/power/mem_sleep. It should print something like s2idle shallow [deep] with the option that is enabled having [] around it. To change the enabled option run echo "s2idle" > /sys/power/mem_sleep. https://wiki.archlinux.org/title/Power_management/Suspend_and_hibernate has more info.
Many modern laptops no longer support S3 sleep at all. It is likely to be an issue with the bios rather than a linux project. On my laptop, with Ryzen 7 5825U, I had to give up on S3 and use s2idle. Also had to pass "pcie_aspm=off" as a kernel parameter because it would take ages to wake the ssd without it. Overall works ok. Not as good as S3 but better than nothing.
It is probably possible however currently I can go to kbin.social/d/9to5mac.com and see all the posts that link to 9to5mac so them hosting their own instance would be kinda redundant.
Yep on kbin you can subscribe/block domains so anything from that domain will show up in your feed. This works for instance domains and general websites that people link to as well. Its good if you want to block whole instances rather than asking the admin to defederate.
I think your first course of action would be to bring this up with other members of your friend group and see how they feel. Have they also noticed this behaviour? Do they have any ideas how to deal with it? It will be easier to help this person if you work together. Just make sure you don't seem like you're ganging up on them. Maybe you can approach them with your concerns and then another friend can bring it up separately some time later. If you want to help always approach with kindness and love.