New to chain rotation: my second chain was a late delivery and as a consequence, the first one has racked up 3,750 km (~2,300 mi) like the rest of the drivetrain. I've kept it wiped and lubed regularly, lately almost on a daily basis to counter some rattling on the chainrings that has affected it in last 1,200 km.

Elongation only showed up recently, about 10 days ago, at 6.001 in. Today it's at 6.007 and the bike's weekly mileage is in the the 400 km range.

Since the chain is now getting longer at a measurable pace, what would the better course of action: just keep it running until it hits 0.5% or clean/relube/store/reuse?