I would like to thanks for this feature.

For me is this working

Prefs/Presets/Monitors/Layout.txt
MAIN Radeon9700M.monitor LEFT
Would place the other monitor on the left side. Needs a reboot.

Thanks Jacadcaps

I created this Layout.txt file and External Monitor gived on the Left side of PB and mouse flip changed to left side, before this change was on the right side.

thx