I wouldn't be too concerned about the JCV and ASR2 files because they're both map-related anyway and change with each version. Therefore they won't work with any version except 2015.10 and new ones will always be made available. But yes, if you want just put them in an SD folder that can't be recognised by the unit. An interesting exception to folder naming is POI which can be named anything and the *.gpi files will still be seen by nuvi units, in fact those files can even be put individually in the root of the unit or sd and still be used. Similarly MP3 files with capable units.

I wish it was that easy to disable the 'on move' lock out in Denso/DVO Dayton units. In them it's controlled by the firmware and linked to the speed registered by the vehicle GPS signal. It doesn't lock out the functions until it senses that the speed is a few kph at least to allow for minor fluctuations in the signal. It also doesn't auto-agree after a short time and will stay on the agree screen forever, not allowing even use of the radio, dvd etc at all even if stopped until the crucial screen press on 'AGREE'. I hate that goddam screen. They even made it mostly blue so to me it's like the pc blue screen of death!

The 800*480 screen nuvi 3790 with early firmware used the full screen 480*270 JCV file same as the 480*272 screen 7x5/1xxx series and the resolution was acceptable. However, that's a 4.3 inch screen less than half of your KW's so the resolution in ppi is already less than half that of a nuvi 3xxx displaying the same picture size image. The 234*212 images will look very pale and washed out on a 7" 800*480 screen for sure.

Amazon has a good history for refunds, so if it's a 2015.10 card even if you've removed the code cover [but not activated it] maybe it's still possible. I know of a person in UK recently who was able to get a refund from Amazon there on a EU LM card purchased mistakenly for a Russian localised nuvi [you can't add another LM region to a nuvi with different OEM mapping data]. He had also scratched the code cover off. Worth a try if it's for the current map.