Changing loop size using loop in point

Originally posted in General Discussion because apparently I can't read and didn't see this section originally, so let me just copy and paste my posts...

Been fiddling around for a while now, but decided it was time to give up and ask you guys - I'm trying to set up a knob on my Numark Omni to control loop size. I got it working using the loop out point (just using the 'loop size' command) but I'd quite like it to work using the loop in point when I have a modifier enabled.

Just to further explain, this is what I want:
- When the knob is turned left, loop size halves (by moving the loop out point backwards)
- When the knob is turned right, loop size doubles (by moving the loop out point forwards)
- When the knob is turned left and the modifier is enabled, loop size doubles (by moving the loop in point backwards)
- When the knob is turned right and the modifier is enabled, loop size halves (by moving the loop in point forwards)

Second post: oh ok - so I just got it half working, this bit: When the knob is turned right and the modifier is enabled, loop size halves (by moving the loop in point forwards)

but the other bit doesn't work.

Here's what I've got set to this knob when the modfier is enabled:
Cue/Loop Move mode, button/hold, set to value: loop
Cue/Loop Move size, button/hold, set to value: loop
Loop size, encoder/relative, inverted
Cue/Loop Move, encoder/relative

Like I said, it works fine for halving the loop, but when turning the knob the other way to double it, the loop doubles (good) but jumps backwards the 'new' loop size. So say I have a 2-bar loop (1, 2, 3, 4, 5, 6, 7, 8). I halve it by turning the knob when the modifier is enabled, so I now have a 1-bar loop (5, 6, 7, 8). But when I go to double it, I end up with a 2-bar loop starting 1 bar BEFORE my original one (-, -, -, -, 1, 2, 3, 4), when actually I'd like to go back to the original 2-bar loop (1, 2, 3, 4, 5, 6, 7, 8). Derp, I'm a bit rubbish at explaining things, I hope you understand...