Darren made a good call with the coils.
The next thing to check would be the pick-ups.
Assuming that you ultra sound cleaned the injectors? Even if they are spotless it doesn't mean they are not worn out... Might be worth swapping those too, to see if the problem goes with them.
It's also worth checking that the electrical connectors to the injectors are making proper contact... I bought my bike as a non-runner and it was just those connectors not making. (I still have a couple of new Marelli plugs if you find you have the need)
My money would be on slightly un-synchronised butterflies, but ending at the beginning, as it were. No carburation issue should begin without a valve clearance check.
Plenty to be going on with...
