This was exactly my thought. It breaks every bit of intuition I have using a browser, and makes pages run even slower.

Every bit of intuition you have using a browser, really? You click a link, the current page changes, you click back, it goes away. You cmd/ctrl click it opens in a new window, you right click and select "open in new tab/window" and it opens in a new tab / window.

	▲	snailmailman 7 hours ago \| parent [-]
		Now, when you click a link in GitHub, the current page doesnt change. I want to look at the linked issue on its own page. That doesn’t occur anymore. The page i wanted to go to pops up in a small overlay on the right hand side. The body text and content that I wanted to view is in a new, weird location, with the old page still behind it in the normal spot. It’s very unintuitive. Thankfully either the behavior has reverted or I’m no longer in the A/B test. I can’t get the popup to happen anymore for me. (edit, nvm, behavior varies depending on repo or something? it acts completely differently on different pages, sometimes links are normal and sometimes they open in a popup. extremely annoying)