Hi all.  I've picked up a Modfactor pedal to go with my TF and have noticed that the thing changes output level in a a big way depending on algo.. selecting chorus for example seems to lift the ouput level significantly.. is this normal?

This is normal, and as st. bede stated, our solution to this issue was to add output level control per preset.  If even the output level adjustment doesn't contain the volume swings for you, there may be an issue.  But I'm pretty confident it should work.