@pixelfed I have concerns about this :

It seems to add centralisation
Block lists have already proven highly problematic due to individual blocking policies and a high number of errors
There seems to be a growing lack of focus at Pixelfed with projects being started but never quite finished (eg the app, which should be the main way to access Pixelfed, is languishing in Beta lacking many facilities and basics)
The name ModDB already exists and is likely to cause confusion