As many of the DL1000 / DL1050 owners have posted before, the 6th gear is like an over drive and thus basically useless for town driving. Going to an 18 tooth counter sprocket may end up with the 5th gear being too tall for town and some country road use.
I helped change a front sprocket on a friend's 1st gen Vee to a 16T, while retaining the 41T rear sprocket and found that the 6th gear was less like an overdrive and better than the 17T/41T setup.
I would imagine that the 18T front would come in handy if one was riding on the Autobahn or similar type of highway.
FWIW, go to
https://www.gearingcommander.com to compare the sprocket size vs rpm and speed information for your model motorcycle. Armed with the results, you can decide how you want to proceed.