I've a couple of problems to report:
The first, I'm not sure if it's an Opera bug or extension bug. Here, a "painter" thread crashes on low memory. It only seems to happen with certain sites and doesn't affect most tabs. Opening the site in a new window always works.
WhatsApp in the sidebar seems to screw up WhatsApp Beta. It sometimes just stops being able to log-in, forcing one to set up a new connection. I assume this is down to the sidebar sending some half-baked transactions.
The thread priority of the sidebar is probably too low for me but this is a slow laptop (early AMD Fusion).
Also, the default of picture-on-picture really screws up playing music on YouTube. Can we revert it?
Lastly, can we have a setting to stop giving small extensions their own thread? It's easy for them to take up 1GB whether they're being used or not.