In the Reaper forum I can update old post as the "Edit" icon stays there after years n years. I just checked the Steinberg forum and it's the same deal as well as many others I would imagine.
If you need to update a post with new links ,new pics or new methods, you can't and have to add a new post way down under all the other posts.
Not sure what the thinking is behind this.
It might be like manuals, all the other companies had their manuals for download but not PG and if you posted a link to the manual it would be deleted.
But now https://www.pgmusic.com/support.manuals.htm

About two years ago, I suggested the time to edit the first post should be extended, so we could edit it to say ‘Solved’ or some such. This was done. I don’t know how long the limit is, but it’s longer than the 24 hours on most posts.

Yes we get the "Mark as Resolved" button now.
It would be good to be able to update our posts like here
https://www.pgmusic.com/forums/ubbthreads.php?ubb=showflat&Number=557642#Post557642
you read the guide but miss the updated comprehensive guide way below.

There can be certain situations where this is useful to be able to do.
+1

I agree.

+1

Yes, I marked that post 'Resolved'. I hope that might lead someone to view the whole thread and see the clarification below.

I did know about Resolved, but it's not just that. You can edit the subject line of a first post in a thread for a longer period than you can edit the post. I don't know how much longer this limit is.