No worries, Peter. A good suggestion all the same.
On the warranty front the words are clear, Thorn do not cover any claim made relating to the damage caused by the fitting of any kick stand. So it does not invalidate your total warranty but any damage caused by any attached kick stand is not covered.
Tubus has a similar outlook, though not necessarily kickstand-related. Their warranty covers failures of the rack in-use for its intended purpose, but they don't cover damage caused by fall-overs and blow-overs, which seems reasonable. Those subject the racks to forces beyond what could be normally foreseen by their designers.
Some general thoughts, springing on from those earlier thread links above...
As for kickstands on bikes, in my opinion the
concept is terrific and very convenient, but the execution leaves open the possibility for frame damage, so over the entire population of bikes it really is a gamble that depends on many factors -- the individual bike and tubing diameter and wall thickness, the load carried at the time, the competency and care of the fitter, any number of things. I fit one to the rear stays of my father's lighter-weight touring bike with no apparent damage resulting, but he was also careful to use it only with the bike unladen. There's no denying they work fine for some people, but it's one of those things where damage may not be apparent till After on some bikes/fitments and then you can't turn the clock back. For warranty purposes, this is a critical factor.
Years ago, I had terrible luck myself with a kickstand mounted to the chainstays just behind the BB. I took great care in the mounting and use and all seemed well until I parked in a crowded rack at uni. I had ridden up the hill, so left the bike in low gear. When I returned from class, I found someone had wheeled he bike back to the limit of its cable to make room for theirs to squeeze in. Pulling my bike back caused the left crank (in low gear, remember, so high torque) to rotate rearward enough to foul the kickstand. As a result, the clamp made some huge crushing dents in both chainstays, top and bottom just rearward of the BB lugs. It still makes me sick to look at it, but by some miracle the frame has continued to ride well for another 56,000km with no tube failure, but still....Man!
Kickstand damage like this can happen if one has a heavy touring load and wheels the bike backwards vigorously to turn around while forgetting to fold a BB-mounted stand (I've seen it happen). Bolting the kickstand to a chainstay-brazed bracket doesn't always help, as the torque can be sufficient to tear the bracket off the stays (I rebrazed one successfully for a friend, had to pass on another as it had cracked the stay when it tore).
For designers and manufacturers, it is hard to predict how a product will be used in the field. One rider's JRA failure ("Just Riding Around") may actually be due to routinely performing jumps off loading docks. A distressing number of people (none Thorn Forum members or owners, I'm sure) seem to derive great joy in balancing on a kickstand-supported bicycle. It seems to be a popular activity among the local uni crowd while texting on their cellphones. This puts a great deal of unforeseen stress on a product really designed to support only the bike or a bike and touring load -- and stresses the frame unduly as well.
My friend with the fore-and-aft kickstands had a distressing number of fallovers while we toured due to parking on soft ground and high winds. This was "user error", aggravated by a low bracing angle that was not sufficient to support a heavy touring load from below in those conditions and a wall-lean or layover would have been a better, damage-avoiding choice in those circumstances.
Click-Stands can also allow the bike to fall over if the ground is soft or if one forgets to lock the brakes, but there is at least no clamping to the frame's tubes. I've had great luck substituting these
http://www.bikebrake.com/ for the bungees supplied with the Click-Stand, and they even help if one is simply leaning a bike against a wall, as I sometimes prefer to do.
In the end, one chooses the solution with greatest appeal for oneself, but the warranty restraints are clear.
Best,
Dan.