Do you honestly think that the Honda will be offensive 1/2 mile away?
At a trial on Sunday I couldn't hear the Honda 1/2 mile away, nor could i hear any of the two strokes. A couple of hundred yards away yes but if that level of noise upsets anyone they would complain if a motor mower was used at the end of the street or if a farmer had the gall to plough his fields with a tractor..
Think about this - how many trials venues are that close to houses/people or have no shielding due to contours or vegetation (trees/bushes). There are always people who will moan at motorsport but I can't see the noise of this bike being seen as offensive and giving them more to moan about.
A roadbike witrh an aftermarket exhaust roaring past your house at 2am in the morning, a 16 year old on a moped with 'race ' exhaust, a yob in a corsa (car) with open exhaust and loud stereo or a MX race (close by) may be considered offensive (I like road bikes & MX!) but a trial - NO!
If you think the Honda is too loud the simple answer is don't buy one!
I won't at the moment because it is far too expensive to throw down a rocky hillside and I can get as much enjoyment out of a bike which is 20 years old and is probably just as loud!