OK the following settings work nicely on a precisely cut 172 bpm drum loop for time stretching. The settings really depend on the length of the loop/number of bars still, so you may want to play around with the following settings.
In this example, LFO1 moves the playhead through the sample/drum beat on behalf of a RAMP waveform, with trig mode set to HALF. the combination of SPD and BPM is chosen to be 32 if multiplied. This is to ensure the ramp waveform doesn’t flip back to a zero position too early. The LFO’s depth parameter is deliberately chosen to be 64 (a multiple of 2) but not fully cranked up to 127 instead, since this would have resulted in wonky transitions (not being a multiple of 2).
These are the settings on SRC page 1 that sounded good on the loop I have used.
And these are the settings on SRC page 2.
Audio example with tempo adjustments made while the sequencer triggers the first bar of a 4 bar loop.