In reply to KeithAlexander:
It'd work, but it would be a bit of a bodge, an axe mounting system is something I looked into when I was developing Figfour but I couldn't find an adequate solution, the extra length tended to make the tools a bit unwieldy.
You also have the problem of fixing, there are two options;
Make the loop free to rotate around the bolt (like Schmoolz) but then you need to limit the size of the loop as it will rotate under its own weight if it's too big making it hard to use, this limits the number of larger holds and slopers the tools can be used on, and also reduces the specificity of the training as the shaft rotating relative to the 'pick' is very different to the way you would move with a standard tool.
Fixing the loop (like Figfour) gives you the option of using a larger loop, but requires a more complex fixing system as opposed to a simple bolt and washers, this is why the Figfour tools use custom CNC tooled fitments rather than off the shelf fixtures.
Otherwise I'd say you'll make gains faster training with Figfours rather than your more aggressive Fusions. Figfour was designed as a training tool, not an axe simulator, the smaller griprests are designed to maximise training benefit. Think how big the screw ons at the wall feel after a session on the small crimps of a moon board, the same is true of Figfour training, your tools will feel like jugs afterwards, but nobody ever got strong only climbing on jugs!
You might also find that the wall are less keen to let you play with your own tool as opposed a purpose built tool designed to be used in an indoor wall, but you could be lucky.
If you still fancy experimenting drop me an email and I'll send you out some old style straps to experiment with, let us know how it goes!
Pete (Alpkit product guy)