here are the FC12 Default Layouts exported from an Axe3.
you can load these onto the FM3, but not all the block types that are controlled will port over "correctly." for example, instead of TremPan1 that we see with the Axe3, the FM3 Layout will instead show Wah2. this is probably because the Axe3 has more block types and the "number order" of the blocks are different between the 2 units.
but this will at least get you majority of all Layouts to FC12 defaults, and you can adjust what needs adjusting.
in FM3-Edit, just go to the FC Controllers view (top right-ish button), then near the word Layouts, click the Edit button and choose Import All Layouts:
again, remember that this
replaces the FM3 default layouts, and that the FM3 and FC12 will share the same 9 Layouts. you don't get 2 separate sets of Layouts for each device. depending on how you use the FC12, this may or may not be an issue.
this is why the OMG9 was created, dedicating some of the Layouts to the FM3 switches, and the other Layouts to the FC6 switches.
personally, i would just setup what you need on the switches at some point. chances are you don't need to use all 9 Layouts to accomplish things on the FM3 (and even the Axe3), and instead can mix and match switches on a single layout, rather than approaching things as "separately" as the Default Layouts do. if you want Looper buttons on the Scenes Layout, you can do that. if you want a Tuner on the Presets Layout, just put it somewhere, etc.
lots of power here. the Defaults are a great starting point to give access to everything. but i think the FCs are most effective when you adjust it to what you actually need, as no 2 performer's needs are the same.
