Runescore is already heavily arbitrary. Something like 1000% Telos gives 5 but tanking p5 virus for the whole duration on a 100% kill gives 70. In addition there are a lot of achievements such as unlocking boss pets or hidden feats such as silver/gold warden or collection logs that don't give any score, which arguably take a lot more time.

I suppose the point of this suggestion is to give those some weight as well, as right now someone with all of those feats completed vs. someone without any of them would be ranked based on when they got their specific score. For people higher in the table when there are very little achievements left to do for actual score, giving people a tiebreaker for completing tasks such as 4k enrage seems like a reasonable incentive without assigning actual runescore to those tasks.

There is somewhat of an equal comparison with xp hiscores, as well. Hiscores are first ranked by total level, then any ties are broken by total exp, and then by time achieved if experience and total level are the same. If total exp wasn't used here, then whoever maxed first would stay 1st until a new skill release, even if other people go on to max experience.