Wow, I had to get a second cup of coffee for this question, @t-a-r-o-t! 😂
I'm not really sure what you mean in regards to posting "crypto addresses for people who might wish to make small donations" to old posts, but I do know there's a rather robust debate in Steemian circles on the topic of what to do with posts past payout.
My perspective is this - in late 2014, I decided to blog on a schedule (on WordPress), and I began writing 3 to 4 blog posts per week. While some content was reused to a point (like the basic framework for my Tarot Tuesday posts), the vast majority of it was newly created. To be fair, in the past year or so, on the advice of other bloggers, I tried posts entitled, "Revisiting" then the original post name, but it just didn't click for me.
How much revenue did it generate?
via GIPHY
So now that I'm here on Steemit, I see any amount of SBD earned on a post as total icing on the cake, and I tend to focus on creating new content, not worrying about the old. And speaking of (because I need cake with my coffee...LOL), think about all the amazing bakers out there who spend hours and hours making creations like this (yes, this is a cake!)-
photo via Charm City Cakes West
The bakers get paid for making the cake, the cake gets eaten, and life goes on.
Not sure if that answered your question, @t-a-r-o-t, but now I'm hungry! 😊