When a new reply is posted to a topic/thread, the whole thread should be moved/bumped up to the top.
Also, all the posts should automatically expand without having to click the "flat" button.
TER should upgrade to modern formats.

Tried and failed?
Other forums (modern forums) use such format and are extremely successful.
How can TER fail at something so successful everywhere else?

If a user abuses the forum by constantly bumping old threads, then they're temporarily banned as a violation of the terms of use.

Premeditated thread bumping and other abuses were going on. That was an experiment that I was glad to see buried and expected it to flop from the get go.

I follow such a forum and it has about 20 regular contributors and about 30 posts on a typical day, so that system works well.

On here there are 100s of posters and probably over a 1,000 posts on a typical day, so it would soon get chaotic.

Just my 2 cents.

It is impossible to follow!