I couldn't comment on below idle performance of fuel injected singles as I have never experienced same, the idle
is not adjustable......but I did try to ride a 650 BMW single on trails a while back. No problem with surging or
just off idle performance but the thing was geared too high and really didn't wish to go slower than 10mph
which did make trail riding hard at least for me esp when coupled with massive weight and tall seat height.
I would think any sort of flame out or surging would be dealt with pretty well with proper gearing which means you'd have to almost count
on installing a larger rear sprocket on just about any dual sport. The person who'd have a good opinion would be Spud of the Zhonsen "china rider" fame.
On a related note I found my injected F700GS to be worrisome off road as it didn't wish to go under 15 mph, did kinda feel like a surge as you fought to go slow. It has an idle speed of 1100. But it's not really an off road machine.
Do us all a favor and head down to Babylon an test ride a Cyclone eh?