I'm not a chemist but I just thought that, since the Mg L-p wouldn't dissolve in SFA or ethanol - pretty much a deal killer - maybe there was a chance that a substance that could dissolve it would also be able to work with the choline. Anyway, a nice ivory-tower theory...
Choline would dissolve well in SFA/ethanol so the "battle" now is to find a magnesium salt that dissolves well in those solvents.