OpenVPN DCO is still under development from the OpenVPN developers, and won't be available until OpenVPN 2.6.0. And it's currently unknown what kernel version will be required to support this feature.
I only meant no improvement in dev 388.1; I really can’t speculate how well it will work in the future. But yes generally higher throughput in terms of internet means faster speeds which as Rmerlin was saying could be done in two ways resulting in more or less cpu usage.