Yes, this actually turned out to be a worthwhile thing. Probably, no, likely, others have experienced issues like this, with other websites. Hope they fix that and some image rendering issues.
I'm finding it irritating that .dev remains active in the System tray if you exited the browser. If you exit Edge in the tray, you can regain some RAM--here, about 3-5%. If you uninstall .dev, you will probably get a message to close all instances, and you have to close Edge in the Systray. Further, .dev doesn't open any faster on here if it's not running in the background. It's also disabled at Startup in Task Manager even though it claims no impact. Might submit some feedback there also.