Would G.INP help if there is another phone line next to mine (the neighbours) was causing interference?
From my experience, all be it on a Huawei DSLAM, while waiting for G.Inp application after ADSL/VDSL migration, this took close to 6 weeks in my case, DS errors were virtually eliminated by DS G.Inp application.
US G.Inp has been applied to my line from time to time but never lasts more than a few days as the application removes the associated US errors and DLM promptly removes US G.Inp again.
Not sure if US G.Inp is even an option on ECI cabinets ?
Regarding adjacent line interference, had an unusually severe experence recently effecting my US speed and SNRM which was finally traced to a fault on a neighbours VDSL line, see rather long thread here:
https://forum.kitz.co.uk/index.php/topic,24606.msg413899.html#msg413899Thankfully this was resolved buy my neighbours ISP (BT) as my ISP (PN) refused to investigate.
So yes, G.Inp application is good and should certainly produce a considerable improvement in DS error rate regardless of source.
Glad to see it's finally being implemented on ECI cabinets, hopefully will be extended to all, pity it has taken so long.