I set mine correct when it was a rolling chassis and then as the weight went in it was at least even either side. Tell the truth I am not sure it changed that much (although I can't remember for sure, I think it increased toe by 2mm each side going from a rolling chassis to a fully built up car but I could be wrong). Too much toe in is not a big issue (increased tyre wear and mid corner understeer), too much toe out can make the rear unstable and should be avoided IMO. Whilst it was a rolling chassis I did take the chance to fit adjustable top links as my turbo S3 did not have them.
BTW you could fit captive nuts to the two bolts holding the shims / radius arm bush in place. I did not and it did take some fiddling to undo them but actually not as bad as I feared.
I have attached a picture of the rear suspension on mine for no good reason other than I think it looks really cool, sorry!