I don't know if it's any help, but AeroCoach in the UK make a range of carbon chainrings between 55T and 65T called their 'Brute' range - see link here:
https://www.aero-coach.co.uk/store/p...k-chainrings-1
They seem to be pretty keenly priced (£150 in the UK as opposed to double that for the equivalent Sugino Big Zen, for example). Might be worth a look - AeroCoach have a good reputation for their aero testing and their Aeox disc wheels.