I own Beholder EC1 and now I own DS2A which is tilted motor design.
With DS2A which have same motors - it is much less precise than EC1 - twice or triple less presise I think.
So it results in bad stabilisation on all axes... I tried to find best Magnetic Link but it didn't helped much.
I did good PID tuning with filters based on analyzed "plant+filters".
May be there is bad support for tilted motors?

And here is demo how motors reacts to hand disturbance:
https://youtu.be/hHL9LptmTCE
Is it okay?

And one more question:
With tilted design - Yaw motor and Roll motor conflicts - so it results in permanent low freq oscillations when both simulatenously trying to compensate... How to avoid it? (with DS2A it's perfect when it's about a horizon, but when I roll for 20-30 degrees or more - in that position Roll and Yaw conflicting to each other resulting in low freq oscillation)