Not to look a gift horse in the mouth but...
The credits I get for completed WUs on Raspberry PI3s seem to have doubled a week or so ago. I like it but is it intentional?

I'm not seeing this as being Pi-specific. My tasks (regardless of type of machine) usually return 666.67 credits each (BHSpin), with just a few odd 333.33's mixed in. The tasks returning half the credit take about the same time to run as the others. I don't fully understand it.