I use aux lights mostly to be noticed and not for looking further down the road as the new RTs have very good headlights in that regard. If you can mount them so they are above the handlebars, that would be optimal IMO. On my RT-P the police lights were changed to Hellas on the police mounts. No one EVER didn't see me or turn in front of me when riding that bike.
IMO getting them as far away from the headlight(s) is best to be noticed. Fork,caliper, or front
fender mounts are also good. On my present RT I didn't want to change the bodywork (around the mirrors) and also look for mounts to get them above the handlebars as on the RT-P, so I just recently mounted them on locked open highway pegs, they are quite wide and down near the heads, very noticeable, but not as low as fender mounting. Will have to see if there's any vibration or if the pegs want to fold closed with the extra mass on them.