Two options available to relocate the factory SV04 filament run-out sensors.  My initial motivation was to move them downwards to provide better visibility to the filament dryer that I'm mounting behind there, however, after starting I realised that both options (no offset and with offset) provide a more logical position with regards to alignment with the spools in the standard location and the extruders. Suggested material is PLA or PETG with approximately 3-4 walls and top and bottom layers with >25% infill.  

The photos show the difference between the no offset version and factory and both versions, the idea of the offset is to position the centre of the run-out sensor approximately with the centre of the spool.  Both options re-use all existing hardware, that being the 2 x M4 bolts with T-nuts to mount to the top extrusion and 4 x M3 bolts to secure the run-out sensors to the brackets.  The M3 bolts should start and cut their own thread into the bracket. 

NOTE: Installing either of these brackets will result in a slight loss of z height, this isn't a problem for me but something that should be considered before installing.  If you ever needed the full 400mm of z height you could always temporarily re-instate the factory brackets. These brackets also do away with the two guide rollers under the sensors, to date I haven’t seen any ill effect from removing these.