You can get rid of a lot of excess lateral movement by doing
a few simple things.
First thing is to drill and tap the case so you can make the U-channels
pivot in the center. drill a 1/2" hole through the U-channel,
and use a 1/2" shoulder bolt for it to pivot on.
For the adjustment part, grind a screwdriver slot in the head of the bolt.
That makes it easy to turn inside the U-channel.
then cut a small piece of 3/16" brake line to fill the void between the
head of the bolt and the C-clip. That alone will take out about a 1/2" of slop
on your laterals especially on long ones like a Max IV.