So after a good nights rest, i was able to run my Odroid C4 from a USB drive.
I think (battle testing will need to validate this), that I have done this in a way that will complement DietPi or at least not compromise it (and it’s tools).
I have done a write up here for anybody interested: [Tutorial] Odroid C4 rootfs on USB drive
I hope this helps, actually i hope this ‘holds’ as I really like the robustness of this project (especially after seeing so many others…)