Is there a concensus as to which layers best for testing other parts? For example if I wanted to test the stamina of disk 7 vs disk 10 only, holding all other parts identical. 

e.g 
aH.7.et vs aH.10.et 

Is there a layer that people have agreed on that would be best for this form of testing?  For that matter, is there a driver? A disk?  Or even a Frame?

I thought Spriggan Requiem would be the beyblade that changes modes to adjust according to the situation. It can change its spin mode to transform it from an attack type to a stamina type in mere seconds but still be an attack type with the right driver. For example, having Left Spin Spriggan Requiem against a Right Spin attack type but you want your bey to be a defense type, simply put the 7 disc for extended OWD and put an atomic driver for increased defensive capability.

---

But that’s only my opinion. If you want to test different performances in attack type drivers, I suggest use a level chip to avoid unbalancing the layer of a Cho-Z group, or use god layers with gimmicks or dual layers with almost no gimmicks at all.

---

Just make sure it’s a good attack type.
If you’re using a bad attack type, you can experiment on it to figure out which combination actually works against high performance beys.