I don't have a resolver on my motor but it has been interesting reading all the discussion on getting them to work with Paul's controller.
Is there a reason why something like the
Analog Devices AD2S90AP couldn't be added to do all the interfacing and maths?
They are pretty cheap on eBay. A quick search brought up several listings for less than US20 shipped.
1pcs Resolver Digital Converter IC Analog Devices PLCC 20 AD2S90AP AD2S90APZ | eBay
1pcs AD2S90AP LOW Cost Complete 12 BIT Resolver TO Digital Converter | eBay