So easier with LENgth as on DT / OT.
I can’t be modulated by the lfo on AR. 
On AR I also used Velocity Mod to modulate Start/End with 1 value offset. That way it can be modulated with a knob.
LENgth / END option is definitely an feature request in my concern.
And would allow Megabreak “granular” stuff!
Megabreak of Doom for Analog Rytm
External midi control of Perf maybe?
AFAIK No modulation of Start / End offset (pseudo LENgth) possible without midi processing brain storming. 