Battery!
9/19 '18
OPW appears to be the culprit in draining my iPhone battery when I keep a tab open 24/7.
Maybe it's also the culprit on my laptop battery, which is having trouble keeping a charge for more than a few hours' use.
(If I thought the problem was just the batteries' age, I wouldn't be writing this post.)
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I took a peek. OPW does very little when it's just sitting there on the page, it's not running one of these newfangled frameworks... it does update the counters, but that happens only once per minute, and it's what you were hoping for, presumably, when you left the tab open. Hmm.
Aha: the "infinite scroll" mechanism that loads more stuff as you scroll down was relying on an interval that fires 10 times a second. While it doesn't actually go get a new page every tenth of a second - that would certainly shred batteries - it does do a little math every tenth of a second.
So I switched it, just now, to actually look for scroll events rather than firing on a timer, and this may help. Hit refresh and let me know, if you would.