Currently MS only does batch firing, however the MS-II Sequencer is in beta testing right now. MS-II Sequencer does sequential plus individual cylinder fuel trimming.
If you see more on this in the future please post links on Moparts.
I would be willing to take the plunge for a MegaSquirt-II if it could do this reliably along with a Wide Band O2 sensor.
I would like to try some 18 to 24 air to fuel ratios on 'lean cruise' but worry that without sequential injection and individual cylinder trimming the engine roughness at low rpms would be too much.
Any idea if MegaSquirt-II can handle operating the EGR valve too?