So you’re suggesting some known insight - wrt to design flaw in relation to NDS serviceability - during development of ND555 - through maybe 2016-17-18, then built in to changed thinking and design ( for better serviceability) from NDS to ND555, when it was released in 2018 ?
In which case it may be a reasonable assumption, or deduction, that this general issue was maybe known or at least the potential was understood, before SuperLine’s started to appear for service, from 2020 or when ever …
Hmmmm 