Mazda camber plates - why camber only?

[1987cp]

I've noticed that this product (and similar products) are advertised to adjust camber only:

https://corksport.com/corksport-mazdaspeed-3-camber-plates.html

For other popular vehicle platforms, it is easy to get plates advertised to adjust caster also:

https://www.jegs.com/i/QA1/122/CC100MU/10002/-1


Why do the Mazda plates not feature easy caster adjustment? (scratch) (shrug)