Crank and BB question

Wow. Thanks for that. One stupid question remains:
Couldn't you get the 1.3mm back by (sacrilegiously) mounting the chainring on the inside of the spider, or am I missing something?

Yes, any adjustment would have to be made at the other end. My post about the actual chainline must have got lost in the server fail, and I've lost the Post-it note bearing the calculation, but a quick measurement gives me 46.5mm to the centreline of the chainring. The same measuring method on an old Goldtec hub gives 45.2mm to the centreline of an EAI 3/32" sprocket. I think the EAI 1/8" sprockets have the same chainline, and Phils about 0.5mm less. Fortunately, I use the slightly wider Mavic Ellipse which gives me a precisely aligned chain with a 0.4mm shim under an EAI 1/8" sprocket, but with a Goldtec you could be 1.3 to 1.8 out of line. You could get 1mm back by machining the inside mounting face of the Goldtec Chainring and not machining the cranks. You should take all that with a pinch of salt, as Goldtec have changed their hub design and I was measuring with the bike built up (on two different bikes), not on a workbench with a decent dial gauge, so take careful measurements for yourself before you start cutting any metal. Even quite good frames could be out of alignment by enough to make a material difference if you insist on getting your chain straight to within 0.1mm.