First plug change.
I totally get where you are going with your carb because I did exactly the same with my 770 avenger but manually because it doesn’t have adjustable bleeds.
The transition bleeds were rich, but when I got it leaned down to the AFR I was shooting for the motor acted a bit weak and glitchy just off idle.
So instead of chasing an AFR I switched to giving the motor what it was happy with.
A little rich on the idle and transition and in the mid 13 to low 14’s at hiway cruise.
In my opinion it runs just sweet as it can be.
In my own opinion your plugs look well into the “safe“ zone.
One step hotter should be ok as well.
I also think it’s annoying that carbs change from one drive to another.
My Edelbrock carb would idle super lean after a shut down and restart for a couple of minutes.
The Holley 770 does the same thing though not nearly as much.
I guess the main point I’m making is to get it close using AFR’s, then give it what it likes from there.:D