Yeah, it would be fine to use with double-chainrings later. The centering won't be an issue if you have tight clearances between the chainring-hole and chainring-bolts. There's the issue of loading the bolts in shear since there no ledge to take the radial-loads from the chainring. But if the bolts are tight, the friction will hold the chainring tight and transmit all the load to the arms without stressing the bolts in shear (actually the nut since it's on the outside).