In an effort for searching for extra caster for the six, I stumbled across a TSB by mazda about cross-caster from subframe misalignment.
In the TSB, Mazda outlines a couple of different procedures that can be repurposed for extra caster.
Including, special arms that are caster compensating.
However, these arms are your standard arm with the bushings adjusted to bring the ball joint forward or back.
I replicated this with Racecar's existing arms:
One last, easy trick is this:
Loosen the LCA bolts and lower the car, then steer right, tighen left LCA,- steer left, tighten right side.
The instant center between the two LCAs will force the arms forward, squeezing out the last bit of caster from bolt hole swap.
In the TSB, Mazda outlines a couple of different procedures that can be repurposed for extra caster.
Including, special arms that are caster compensating.

However, these arms are your standard arm with the bushings adjusted to bring the ball joint forward or back.
I replicated this with Racecar's existing arms:

One last, easy trick is this:
Loosen the LCA bolts and lower the car, then steer right, tighen left LCA,- steer left, tighten right side.
The instant center between the two LCAs will force the arms forward, squeezing out the last bit of caster from bolt hole swap.