[j-nsp] Enhanced MX480 Midplane?

[Karl Gerhard]

Hello

this article is mentioning an enhanced MX480 midplane. This is the first time I hear of that: CHAS-BP-MX480-S (=Non-Enhanced) vs. CHAS-BP3-MX480-S (=Enhanced)
https://www.juniper.net/documentation/en_US/release-independent/junos/topics/concept/scbe2-mx480-desc.html

Is there anyone who can give more details about the enhanced midplane?
As far as I understand the cross-coupling of clock input is only related to SONET/SDH stuff, is that correct?

Regards
Karl