I bought my FL1 already converted to mondo style. Mate yesterday was interested in it and asking about it and we got talking all whether we could refit the propshaft with an in-line electromag clutch so it can run in 2wd but put it in 4wd for off road.

The thought had gone through my mind previously but interested to know if anyone has tried it or if it would be a bad idea for any reason? / Or a better way to do it?

I know it's not cheap. I'd need to buy a new VCU and propshaft, plus a clutch assembly and housing, and rig supports for it, modify the propshaft, fit it all somehow etc. Probably not worth it realistically but interested to know if it's ever been done and the practical side of it?

The AWD system is designed for VCU use, so the gearing between front and back axles is different. This means a solid coupling between front and rear would literally destroy the IRD or rear diff due to constant axle wind-up.
The VCU is difficult to improve upon, as it gives permanent AWD, but allows for both slippage on road, and on very slippery surfaces, helping maintain traction.