I am not much of a lab monster, but I did find something pretty interesting. (I am not sure of its value yet, but time will tell)
Atro has a double low string called Five Inversions. (1,1,2,3)
The third hit can be cancelled into Boodnado offering another mix-up when he has pressure.
However, I realized that with trait, you can perform a full combo after the last hit.
1,1,2,3, Trait, MB Bloodnado, B3, J2, D2, Bloodnado, ender
The timing is a little tricky. You have to make sure you hit the trait button right as the last hit is being fired. You then have enough time to combo into his standard MB Nado' combo. My skills are not what they used to be, but even I can hit this 50% of the time after 5 minutes of practice.
This can be done mid-screen.
It offers Atro another pressure string when trait is active. I have not tested it fully, but I believe the default timing on the pickup will protect Atro from MB B2.
Mixing this up with F223 might be a good option to open people up with trait.