I'm not a pilot, but on a similar sized commercial aircraft we were getting Tech Log reports of the plane needing aileron trim input to fly level, we did all that the MM allowed except for adding a fixed tab which, as it was a lease, was not allowed by the parent Co.
After receiving a set of wing boards we checked the T/E flaps up, they were set in limits, the MM allowed small adjustments for the condition of level flight; the adjustment was at the mountings not the drive shafts; we adjusted by 1/4" out; the report back was level flight improved, but when flaps lowered a dramatic difference the other way!
Not my place to warn but asymmetry has to be detected early and managed by the system quickly. My experience is that a drive shaft break is highly unusual, but contamination in the signal generators with water condensation was the most common problem on this model.