So, it was a sunny day today and I decided even with my bike's potential to break down, I would risk riding to work and enjoy the Spring weather.
And yeah, it broke down again. Same symptoms as listed above.

I had a spare sensor with me, so decided to swap that out. Didn't work.
Played with the fuel pump sensor wiring by hand - just tugging here and there looking for a loose connection. Didn't work.
Slammed down and back up the side stand, thinking maybe that the engine cut-out wire when the stand is down has something to do with it.
Then it dawned on me. Engine cut-out wire! 11 months ago I posted THIS.

I surmised that during the ECU swap, this spliced wire was probably tugged and now loose. This led to the erratic and intermittent cut outs, and the more KMs I added post-ecu swap, the less stable the wire was becoming, causing this to be a progressive issue.

Once the Right Switch Leads Wire Covering was opened, the problem wire was found!.
Frayed wire was repaired and now this CASE IS CLOSED.