...My other idea would be to re-attach the tie rods in a manner that would slow the steering response.
A good thought wheelbender & while I designed mine with adjustable steering sensitivity via multiple mount points for the tie rods, the KMX Kart is a "direct steer" - the handlebars are mounted directly to the spindle assemblies with just a cross linkage that connects the two so they turn in unison (prolly a good alternate place for a damper). The only equivalent possibility for a direct steer system would be to increase the length of the handlebars... but I don't think a taddy w/apehangers would quite work as planned
KMX direct-steer w/damper to spindle assembly;
Pic of the T3's steering during construction, note the "extra" hole in the mount plate on the handlebar cross-member, should I relocate the linkages to the upper, the ratio is almost exactly one-to-one & a bit too sensitive for my taste on the street but would be great for closed track course w/twisties. Dropping them to the position they're currently at reduces the sensitivity by a guesstimated 20% or so, still a bit touchy at max speed but allows me to keep the ability to make a U-turn on a two lane road w/o shoulders. I could reduce it further elsewhere, but I like being able to U-turn lol;
A unicycle is less twitchy and inherently easier to steer than any type of tricycle.
Don't need a steering damper either
Sorry scotto, but that's so far off can only mean you're yankin' chain - or you've no real taddy time... or unicycle for that matter
Bicycles, (yes even unicycles) being lean-steer don't have to be concerned with steering ratios. Delta trikes need be concerned but can't do anything about it, as the handlebars are connected directly to the forks/front wheel it's an inherent one-to-one & a damper is about the only option.
While some tadpole trikes have or can have adjustable sensitivity (indirect steering), almost all factory built tadpole recumbents simply don't have a steering ratio designed to be used in excess of an average 15-20mph cruise. Sure, even the HPV only ones can easily exceed that but the steering is set for average, not maximum - else it'd have a slow response & terrible turn radius for the pedal speeds they're most likely to be used at.
This is not a flaw in the design, it does what it's intended to do quite well - it's just something that needs to be accounted for with any increase in average speed is all, as would any vehicle that doesn't lean-steer.