Just an idea:
For a next HF I suggest automatically disable witnesses after reaching 3 thresholds:
- last produced block > 30 days
- last witness update > 7 days
- last price feed > 24 hours
In order for a witness to be automatically disabled, it would have to meet all 3 criteria. This would automatically remove old witnesses who simply gave up the job without disabling first for some reason. I consider it a good alternative idea to use just the price feed criteria alone, but for 7 days.
But I still defend my other 2 proposals: Vote Dilution and Vote Expiration, specially the vote expiration part as I believe witnesses have to keep earning our votes by their continuous work. Some PeakD developers agree with me on that.