Russell, first off, welcome aboard the good ship VAF
I feel your pain, having just gone through a similar issue with my 10----just got it home yesterday after a total left side ignition failure on a trip to Yuma.
Please give us more info about the ignition system that is having issues-----who makes it, what model, does it fire all top or all bottom plugs, or half and half??
How many coils are there? Does each coil have one, two or more plug wires going to it? It is pretty common to have a coil firing two plugs, but you stated the EGT showed only one cylinder dropping out, so I would suspect the coil is still good, and the plug is shorted. But that is strictly a guess...........
For what it is worth, I installed a pair of borrowed mags---(thanks Andy

) to fly home on when mine quit---------just an option to keep in mind if there is a problem finding someone to work on the electronic stuff.