I think there should be some incentive for that, like make those kinds of comments a spotlight or something. Maybe make a community called “late replies” that showcases the best such replies, or have a rule saying they grant free karma (in Reddit’s case).
Wait the save button can remind you on Lemmy? Is this on the desktop? I don’t see an option on the Voyager app at least.
Well it can remind you if you happen to look at your list of saved comments! But no, I’m not aware of any clients which have implemented timed reminders yet, unfortunately.