you shouldn't be getting a "too rich" that's just really weird, and honestly I didn't even know they had a too rich cell.. I have fuel cut all the time and in my brother's msp with the 400cc injectors have had it bogg down like crazy and never got a CEL for being too rich, first of all, I would check your coil packs.. those seem to go bad a lot and cause really rich and bad afrs, and is mainly noticeable in boost.. so I would switch those out...
you shouldn't be going from 1 fuel cell to another with such a drastic change.. I noticed that when I tried to add fuel at like 6.5k rpm so that it would go around 11s and not 11.8-12 afr, the more drastically I changed it from the previous fuel cell values, the worse it got, it would just get leaner and leaner for some reason.. so I went back and made a more smooth transition and it worked... I would change the coil packs and then start from a less modified fuel map, like I said, the fuel cell values between "touching" fuel cells shouldn't really be at a difference of more than +- .2, if you can, keep it at around .1 and gradually change them.. it is also a lot harder for you since you can't data log, but I noticed that when the lower psi ranges are still rich, it can cause you to bogg down when you go into boost... so I would work on tuning your lower boost values throughout the boost range, it helped mine a ton.. also I just saw you have the 450cc injectors.. start with the 440cc map, and the ones I have looked at, at much much lower fuel cell values than 9.4 or whatever you said, some of those are in the 8s and stuff.. but look at those maps and try them out