Do these 3 fuels require different ignition timing for the same motor?

Require? No. But your optimal timing will likely be different for each fuel.

I'd love to see some A-B-C dyno testing for questions such as this, (finding optimum timing for each of the fuels). But then, optimum advance would probably be different for almost every engine combination, no matter what fuel.

For me, the best A-B-A testing was at the track even after being initially run on a dyno.

With MSD Grid ignition all timing changes are a simple keystroke. The data acquisition files record what timing was used for further reference when determining what actually worked best in your engine.

Not required, but if you're changing fuel for better performance, you'd definitely want to optimize the timing as it would be different for every fuel and every octane.