I thought it must be easy to redesign the Motion Lines node into a new operator resembling the famous mograph tracer object from c4d. It seems that all that has to be done is:
1) Decouple the particle position sampling rate and the traced object speed/velocity so that the object is traced all the way irrespective of its speed. Sampling modes: uniform (at regular time intervals) or adaptive (if the velocity rises above a threshold the sampling rate increases by a user-defined multiplier and decreases accordingly if the velocity falls below the threshold).
2) Limit total maximum number of segments / sample points of all the splines but not their length. If the limit is reached, random source particles start getting skipped by the operator. Percentage of the source particles used by the operator may also serve as the limit.
What do you think?