Here you go!
These are the three re-engagement episodes:
https://www.onsequel.com/channels/24685/episodes/45839/trees/45830
https://www.onsequel.com/channels/24685/episodes/46446/trees/46437
https://www.onsequel.com/channels/24685/episodes/46444/trees/46435

Indeed, would love to see this added though!

I see, this could work, thank you! / But would love to see an easier solution for it!

Well, I'm afraid not.
I would like to re-engage at a specific time, but in the time zone of that user. (I don't want to wake people up at night)
I would also like the user to specify the time and frequency of re-engagement (that's why I'd like to specify the trigger time for the re-engagement node with a variable).

And if I do that, won't it interrupt users that are currently using the bot?

E.g. I want to re-engage users at 5 pm in their time zone if they have been inactive for at least 12 hours. But I do not want to re-engage users that are currently active or that have been active recently. I'd also like users to pick at what time and what days they would like to receive the re-engagement reminder.

My use case is: I only want to re-engage some users, but other users should not lose the progress in episodes that they are currently working on (but have been inactive in).

E.g. user A is working on episode 1 but is taking a break for 4 hours

user B has completed episode 1 and has been inactive for 4 hours

-> I'd like to re-egage user B, but not user A.

If I trigger the re-engage node for all users, user A will need to start over again in episode 1.

For example:

If a user gets in touch with the operator, then the operator could alter variables that were set for this specific user in error.

So say user A paid for premium services in the bot, but somehow didn't get these, the operator could then update the variable that stores if the user has made a purchase - and trigger the right episode.