automatically time-strech ?

Hello,
can you put on a wich-list the ability to automatically time-strech sample to a multiple of loop please ?
i.e. BPM = 120 so a 4/4 loop are 2 secondes and if we open another loop-instrument, we can time-strech to a power of 2 lenght of loop (put 1, 2, 4 or 8… loop in mean loop) ?
Excuse my english level, I’m french.
Thank you.
Best regards
Ludovic Ruiz

Feature requests go to http://tracker.ardour.org/ please.