Heey Ched, I’ve tested loading your pedalboards a bunch and so far, no freeze. May I ask you what version you are using on your Mod Duo? I would suggest you to try the new Release Candidate:
Release 1.11.0-RC2
The upgrade procedure is explained at the top of our releases page, here:
http://wiki.moddevices.com/wiki/Releases
Let us know if this fixes the issue or not!