the problem with telemetry data is that sometimes you can accidentally collect sensitive data without realising it. i know one library on iOS was collecting the coordinates of all touch events. however, that meant it was collecting the coordinates of all touches on the keyboard which made it possible to reconstruct user input into password fields.

You’re right about there being a problem with it.

Which library was/is doing this? Would like to avoid it.

Which is worth nothing if it can't be examined and verified (not to mention it can change with any release).