Wiring issue still relevant today. Plugged in using instructions, didn't work. I thought I fried my main board by reversing the wiring and seeing a puff of smoke and a flash. Turns out it was a fuse that strangely, was still good? Set up back the way they had wired it originally then moved blue pin to z-stop and it worked fine. Thank you for pointing out that the blue wire, and not the white wire is the sensor. Guess I got lucky, printer still heats up the bed, nozzle and all axis function properly...
Am I better off calculating power draw and buying supply in advance, or testing with a bench supply?
I would say calculate, with a good margin. The link above is a good resource for analyzing your power budget.
Do you plan to run the heat bed on mains voltage or on DC? This is typically the main consumer.
What voltage do you plan to use for your servos? 24V is common and better than 12V.
You want to get a power supply from an established brand such as Meanwell and buy from a reputable vendor to make sure it's not a clone. That's safety. I like their UHP series because they are compact, efficient and fanless.
If you use an SSR to control the bed heater, again, you want a good brand from a good source. That's safety related.
You've spent more time avoiding posting useful information than it would have taken to provide. If you had provided them, and no issue would have been found, you would very likely have had your warranty approval by now.
Plenty of warranty claims aren't warranty, they're wiring or other issues that can be found by helpful do-gooders like myself and others. Many hands make light work, That's kind of what the point of these forums and open-source in general.