The maximum spectroscopic (split) ratio supported by 10G EPON is?

In HCIP-Access teaching materials, 10G-EPON improves optical budget and FEC efficiency compared with 1G EPON, enabling very high split ratios. While commercial deployments commonly use 1:64 or 1:128 depending on optics class and reach, the maximum (laboratory) split ratio often cited for the technology is 1:256 under favorable conditions.