1 When top en back are identical (same file, same type of wood):
You can feel that the back is clearly vibrating more than the top.
Damping the back does effect the sound more than damping the top.
There is no real difference in sound if you make a “mirror” violin or if you string the violin “ left handed”

2 If the same profile for back and top blade are used:
Different types of blade profiles with the more or less the same weight do not change the sound much. The lighter the better.

3 the bridge needs to be made of a hard type of wood that is not heavy.

long legged bridges are not so good.

I currently use Hornbeam..

4 supports:
Bas bars as in classical violins, work.
Small saddles across in the curvature in the arc work better. They are lighter and the cross grain helps a lot.

5 When the top is lighter than the back (thinner)
the sound does not notably improve.

6 When the back is lighter then the top(thinner)
The sound does notably improve. More high.
(I made one instrument with a top of maple, it did not work.
So the top probably need stiffness, not weight.)

7 There is a noticeable improvement when the top and back have differed profiles:
The top with a stronger curve then the back.
The “bite” improves and the a and e strings start to sing out.
It feels as if the top (under pressure), react different to vibrations then the back (under light stress)
This is stress and pressure caused by the pull of the strings and the pressure from the bridge.

 

In a way the Dutch Violin is a violin up site down.

 

This has a interesting advantage:
You can finish the violin, varnish all but the back, string it en test for sound.
Now you can scrape, sand and “tune” the back. There is nothing in the way.
Testing and adjusting without any interruption.