Hello, We have a one problem in Russian Wikipedia. Cyrillic symbols = 2B, but Latin symbols = 1B. And because of that our 'summary form' can include half as much than EnWP 'summary form'. Is it possible to change it?
Not really. Not easily. The limitation is caused by the length of the database field. That can be changed, but the database schema change would require updating all existing page revisions, which is terabytes of data, and therefore difficult to execute without site downtime. It's a long-standing request, since 2006 ;)