I think it's really just timing and who looked at their journal notification number climbing up. I legit think some people don't have anything better to do if they're waiting for hours. Sometimes I do this in several bus rides to work.

Also some people use third-party website scripts that gives push notifications.

Any idea how to find these push notification scripts?

Sorry, not really. I tried setting up scripts on my web browser but all the instructions were either too advanced or too vague that I gave up and just nab slots when I see (and can afford) them.

There's a telegram bot that you can sign up for. I think it's called FurryArtWatch bot or something. You can set it to watch certain artists for you. It will send you telegram messages whenever that artist posts anything.

it has a delay, and it's not perfect, but when an artist makes a post about them opening comms in a later post like pak did, you're a lot more likely to catch it.

hope this helps.

Maybe specific artist can send you note about it, if you ask them?