@resynth1943@banana.dog I have been searching for my past posts, but didn't find it yet -- I had a link to the actual git hub page with the issue being brought in, and Eugen responding, briefly explaining some reasoning for his preference, and closing it. Was around 2017 or so.
There is no technical reason, as witnessed by many instances having higher limites.
He explained he had concerns about visual instance timeline display being overwhelmed by larger posts; not really a problem here, as they do collapse in size, after a certain point.
However, he's the one in control, and it's his idea to have the 500 chars limit hard coded - and in multiple places. I have requested changes from some admins, and one responded it was too much work, as it has to be redone after each update or upgrade.
Eugen is a bit of a control freak, but he's accomplished a lot.
Good that we can look at competing examples of compatible software - like Pleroma, Glitch Soc, etc.