GT Carbon Sensor Expert 2016 Rear Gear Cable Routing Issue

Whilst diagnosing poor down shifting I came across an issue with the rear gear cable. It had rubbed away and created a rut in the frame. The picture below shows this with the bike upside down and with the rut highlighted in yellow. Viewed with the bike upright from the back with the cable removed. The red box highlights the rut.
The pictures below shows how the gear cable was routed through the rear suspension area of the frame. The red line highlights the gear cable, and the yellow circle highlights a nick in the cable. I think the nick was maybe caused by the gear cable rubbing against the suspension link.



With the bike upside down the picture below shows where the cable was routed through the frame.


So now I've sorted it. I installed a new cable and ran it alongside the front gear cable, bypassing the frame entry point, and have cable tied it to the front mech and gear cable in a couple of places.