Having a brief look at your log files one thing ive seen on the start of "fing_lean_spike" is the drop in MAF readings in relation to the near linear climb of RPM.
I seem to think there is a MAF reversion issue. in a nutshell phantom airflows created by valves closing and sending pulses of air back past the maf, more severe when your place the maf closer to the intake manifold. I notice you've scaled down base maf table but reversion tables may need addressing to iron out these lean spots, or more the point desensitize the maf as to smooth and make commanding fuel more true to whats needed by the engine.
Take a look at these snapshots that ive taken in relation to this instance that I'm talking about and see what you think
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