Balance of a bare bow

What a bare bow shooter wants to achieve is, getting the center of mass (COM) at the same place or slightly forward and below the pivot point. A slight forward rotation is ok because it lets rotate the arrow rest wire downward and away from the arrow.
The standard riser design with standard mass distribution produces a bow with the COM behind the pivot point and thus, a bow with a tendency to rotate backwards and lifting the arrow rest at release. The only reasonable measure to do something against this backward rotation is placing weight in front of the pivot with a stab or a weight module.
Adding weight to a riser always has two effects.
1. it increases the mass of the riser and minimizes the reaction of a riser to a force that is applied to it.
2. it has an influence on the position of the center of mass (COM), unless the additional mass is added just in that COM.
It is important, to place the additional mass in a place where both effects help reducing riser movement at release.
There are mostly only two mounting positions that make sense in that context.
a) The middle and
b) the lower stab bushing in front of the riser.
...and the weight should not disturb the optical appearance of a beautiful bow, which in my eyes is always the case, when I mount stainless steel cylinders to the front of a riser.
Both positions have an influence on no 1 (mass) and no 2 (position of COM).
a) good effect of moving COM forward, weak effect on positioning the additional mass far away from COM to get best lever effect for the additional mass possible.
b) intermediate effect on moving COM forward, good effect on placing the additional mass as far away from the COM as possible.
So, the best would be a compromise between the two mounting positions and that is why we designed the weight modules for the Vanquish and the other Stolid Bull risers in the way they are.

Stringwalking effects during release

With string walking you always get a very hard vertical impact on the arrow at release.
This is caused by the fact that you pull the string below the arrow and not at level with it, like with a mediterranean release.
At release the upper part of the string is already under tension and the upper limb immediately begins to pull the arrow. At that time the lower part of the string is loose and the nock point thus is raised upwards. When the lower limb has stiffened the lower part of the string the upward movement comes to a sudden stop and the limbs begin to work together and accelerate the arrow forward.
There are videos available on the internet, which show this effect very well.
The first lift of the nock is that strong, that the complete arrow is set under a vertical oscillation with a considerable amplitude. This oscillation will not be damped quickly if you shoot an unfletched shaft and it will be even worse when shooting over the shelf without a damping arrow rest wire.
If you are irritated by your vertical behaviour of your bare shafts and want to find measures to minimize erratic arrow flight, you always should have in mind, that the arrow is undamped by vanes and it will show these vertical oscillations for a long flight until the inner damping of the arrow material calms the oscillation down.
What I want to say is, arrows shot over 20 yards that have their nocks low can show a completely opposite picture when shot at 30 or 40 yards.
I personally do no bare shaft tests on a bare bow with string walking because the results are not worth it. Put vanes on the shafts and enjoy small groupings. That's it.
If you want to test, whether a shaft fits to your bow, then do bare shaft tests with mediterranean shooting style. Such tests are very useful and absolutely sufficient to find out whether an arrow fits or not. It is mostly not helpful to bring too many variables into an equation.

Stringwalking effects on arrow spine

As a stringwalker you always have to fight with the arrow spine.
With 3 under and index finger touching the arrow, you nearly have a "normal" draw length of a mediterranean shooter.
With considerable amount of crawl on shorter distances your effective draw length shrinks.
How much the shrinkage is, can be measured by observing the arrow tip on the riser by a second person. It can be as much as 1/2 inch or even more.
If your arrow is perfectly tuned for long distances, it will be too stiff for short distance crawl, due to the "shorter" draw length, and thus have a tendency to the left (for RH shooters).
So, my hint would be to tune for short to intermediate distances and accept a slight right-tendency (arrow too weak) on long distances.
You need more precision on the shorter distances because that is, where you get the big points.
If you shoot with a plunger, then take a plunger that is readjustable during the shooting.