Synchronizing clocks with C++

Continuing the discussion from LimeSDR ext ref clock freq and type?:

I’d like to synchronize the clocks on my two LimeSDRs as described in this post. I’m connecting the CLK OUT from one to the CLK IN on another. However, it doesn’t look like I am able to change the setting in the Si5351C module as it doesn’t use an LMS7002m register.

Is there any way I can set this option through the C++ api?

Which model LimeSDR boards?

The LimeSDR USB-A boards

Does this do what you need?

It seems like it, which of these clocks is being output from the CLK OUT port? Is it CGEN?