can you adjust the speed of a loop in karma~ *without* pitch shifting? or is there another method?

I'm trying to build a patch to integrate with my eurorack setup that would generally work as follows:

1) set a loop length on guitar to act as the "master clock" (i.e. things sync to that buffer length and divisions of it)
2) as the performance continues, have the ability to lengthen or truncate the "master clock" buffer (and, therefore, lengthen/truncate the other things syncing to it) without changing the pitch of the original loop

karma~ seems to be the ticket for almost everything, since the loop length can be decided on the fly and various timing divisions can be culled from the current position output, but I'm not seeing a way to time stretch/smush the loop without changing its pitch. Is this possible or is there another looping/overdubbing solution that I could use?