Some close ups of the PTFE guide with runout sensor mount for @Jonathjon. Gray wire is Cat5 for the power/signal to hotend’s CAN Bus EBB36. Ideally I would have clipped wiring to underside of rear top X extrusion, but my wiring is too short, hoping to redo that at some point after critical features like gratuitous lighting are taken care of 
Hope that helps, cheers!