I was wondering what technical constraints required this cut-off of debate and if an exception policy could be instated ?

The reason is spam prevention. Spammers like to target threads that are no longer active, and add their blocks of links. No one notices...until you link to it as a reference and find a thousand porn links appended.

If a discussion that is still on-topic and productive has "timed out," feel free to continue it in a new DrumBeat.

And I have seen this elsewhere.

You're doing a great job here, Leanan

8D