I've been trying to experiment with richer AFRs but it seems I've hit a wall.  I replaced the fuel filter thinking it was the issue but now I'm starting to think it might be tune related after looking at the logs.  It's a stock 1.8t with ev14 550 injectors and otherwise healthy.  Any thoughts appreciated!

I've attached two graphs with different AFR requests to compare.  I'm considering trying to fuel with BTS as an experiment.

 

Corresponding logs attached.  It looks like the injector duty cycle doesn't really change even though the AFR desired is clearly different when comparing the two logs.