So far as I KNOW in A-class, only the commercial Marstrom boards are assymetric. All others appear to be symmetrical, but there is discussion/controversy whether they can/should be canted forward to provide a positive angle of attack. Also there are several opinions on location: fore, mid or aft between front and rear crossbars.
IMHO, None of this is clear to the builders/experimenters. But you are allowed to buy a new A-boat for $US 25,000 based on your best guess!