The hitting the tank thing is not good however....
You only have to adjust your lockstops. Easy peasy. Its only a problem if you DONT adjust your lockstops! (I used a longer stainless steel cap head bolt and some washers) I only mentioned it so you dont damage your tank in the first 10 seconds of fitting it - like i did as my bars swung round. Luckily my tank was brand new and still in primer so the little dink I put in it was dealt with when the tank was painted.
BTW you will still have the same issue with the Skunkwerks one as from what I can see its even bigger around the stanchions than the BMW bottom yoke. Also you will pay customs charges, a Parcelforce handling fee, tax, and postage - I did look at this about 3 years ago and it was a showstopper (for me anyway).
As for geometry - I noticed no difference whatsoever in regard to that but the overall improvements far outweighed any "negative" impact on the geometry (not that I noticed any as I say)
And also (IMHO) whilst it looks a decent bit of kit it still looks a bit "aftermarket" and sort of a bit to modern for the G/S.
Edit
I have just looked at the Skunkwerks one again, and precisely where it is thickest (the clamping bolt area) is exactly where it will be hitting the tank, and is much thicker than the BMW bottom yoke.
Also per Beemerboffs post - once the top surface is milled the indicator stems can be fitted by flipping them over (and maybe side to side to, cant remember), the bar mounting is simply 4 holes to be drilled (you can use the old plate as a template) and yes you will need to drill 2 threaded holes in the front of the yoke to fit the binnacle brackets (which doesn't seem possible on the Skunkworks one BTW - seems much thinner there)