A couple of questions and tossing out some ideas for things to try…
1. You mentioned it’s a new chassis so why is the right spindle dropped one spacer? Was this to compensate for the cross weight or something else?
2. What do you mean by seat positioning is maxed out? All the way back or butted-up against something? (I’m guessing this is a tall driver and you don’t want to move seat forward.)
I’m not familiar with the setup on an Lo206 chassis, but the numbers you are shooting for are pretty standard for most karts. It might require mounting weight at the front of the kart to achieve those % (based on where you are now). Try scaling again, and rest the weights on the front center of the seat and your legs (just over the front seat tabs). This should give you an idea if it’s possible to get enough weight forward without actually mounting the weights. My guess is you’ll either have to mount a weight up near the steering shaft (not recommended) or move the seat forward a bit.
As for the cross weight: That can be caused by minor movements in the steering when scaling as well as one tire slightly larger than other side. Did you make sure steering geometry is set correctly (toe, camber, caster) and then scale several times to make sure you get consistent readings. Also measure your tires to make sure they aren’t the cause of the cross-weight.
The right spindle thing is kinda weird, but you can easily fix a tweaked chassis (if that’s the reason for it), but jacking it up on one side and jumping on the other (lightly). It’s done all the time, but don’t worry about that until you let us know why the spindle was dropped.