I know of several procedures for tuning a vertical bow. What comes to mind are paper tuning and adapting the arrow's spine.

I know these things CAN bedone in CBs, but are they normaly done? Is there any need or value to it?

for the most part, most of the tuning on CB's is the arrow & string. working out a combo your CB likes usually the heavier arrows with very good FOC will give the best accuracy but not traj.

Not much you can do to tune the C bow. Should not loosen the limbs differentially, and changing the nocking point can't be done. Like Smoke says, about all you can do is play with arrow weight and string tension. I've found that arrows with lots of FOC (mine are over 20%) with small vanes and equally small, preferably four-bladed, broadheads gives me the best accuracy and consistent flight from arrow to arrow.

I don't think that there is near as much to tune in your cross bow set up.... with other bows you have to watch the spine of the arrow and you can work with the string, nock point, etc, but as long as the bow is straight on the barrel and the limbs are set the same and nothing is loose, you then just see what it likes for arrows, heads and weight distribution... and vanes or feathers... there is a lot left to play with if you like to tinker, so you do not get too bored..
dk

I don't know how true that is. If your spine is too soft you will loose energy to archer's paradox. Cam lean looks like an issue. I made some strings for a lark for a Ten Point and the yoke at the cam allows for adjusting string lenght to the end of the limb for what looks like cam lean. At minimum tuning can make the machine more efficient. Just my thoughts and I might be wrong. For minute of deer accuracy I think most of this matters not.

I agree :-)

At one time (early on :-) I onwed a Buck Buster. Right out of the box it would not group the way I thought it should. I finally looked at the cams' rollover and they were way off (from the factory). I evened them out and the bow shot much more accurately.

I find the arrow that shoots the most accurately within the weight range I want to shoot and go with it. Not much tuning to be done with a crossbow that will result in a world of difference in accuracy.