Just my $.02,
Since Pro-E 2001, I have always used absolute accuracy, set to .0001 or .00005. My parts are forged or machined aerospace and medical parts approx 12"x12"x12" or so with lots of draft, fillets and rounds.
I know this has been said before but relative accuracy of .0012 means that the smallest feature on the part is approx .12% of the length of the diagonal spanning a box enclosing the part. Also, the relative accuracy never gets finer, only coarser. So if you start with a large block and whittle it down using cuts, the relative accuracy is based on the largest envelope.
Absolute accuracy is exactly what is says. An absolute accuracy value of .0001 will allow edges, surface patches, etc... down to this size.
I agree also that your start parts have to be modified to have this accuracy as your default. At one time (before WF4, I think) if you imported an IGES or STEP part directly into Pro-E, it would not use your start part, but create the part with .0012 relative accuracy. The work around was to start a new part first, set the accuracy to .0001 absolute, and then import the step file using something like INSERT | SHARED DATA | FROM FILE... Lately, when you try to open a STEP file directly into Pro-e, it will now ask you if you want to use a default or specific start part, and I think that there is a config option for this as well.
Christopher F. Gosnell
FPD Company
124 Hidden Valley Road
McMurray, PA 15317