Hi @ats-david
I'm wondering what you would define as the witness voter being active, be it a proxy with stake, or the individual vote.
last_post, last_vote, or perhaps last_bandwidth_update?
I ran some stats on 180 day vote cancellation a few months ago, and the conclusion I made was that this didn't move the positions round much.
I'm thinking of doing a repeat for 365 days 'inactivity', and perhaps 100 days extra for the 13 week decay proposed by you.
I think a year is plenty of time to interact - vote/post/change a witness vote. Decay sounds fair but tricky to implement and I think just dropping the vote after a year is fair enough.
Whether it will make much difference to the ranks, I'll take a look....