So, got my PSU yesterday. Compiled 4.3.3-zen with -Ofast + those patches, quirk
removed and firmware added to initrd. Modesetting works, I'm able to see
Plymouth finishing its animation. However, at X start stage I get a complete
hang, but monitor's active. It's likely a PM error, as else there would be a
hang at modesetting stage. It's similar to an issue I had when compiled the
kernel with quirk containing my card's normal MEM and CORE clock values - hang
due to PM error.

Should I do something else? And is there a way to make the card work at its
normal frequencies?