The concept behind four-stroke specific chassis is more down to budget and a couple of ergonomic tweaks rather than chassis construction/handling differences to accomodate your typical inboard drive OHV engine.
For example, they may come with a simpler camber/caster adjustment system, come conventional wheels and bearing carrier materials, different rear cross bar position, different seat bracket, inboard drive key on the axle.
With the KA100 potentially being a two stroke budget option, those same chassis models for “four stroke” are sometimes offered as a KA100 chassis.
So, I wouldn’t rule one in, or out based on them being used (Marketed) as a four stroke chassis.
More info on four stroke chassis (still sounds like an oxymoron to me 
) here: