EC300 Running Rich in first half of throttle

[Delphinus]

I have a 2007 EC300 with the AS1 (screw top) PWK 38 carb. It runs fantastic at full throttle, but not so great at low (0 to 1/2 throttle). Bogs down a bit before pulling away, and I've had a few examples where I've started it, it runs for a bit then dies and won't restart. Cleaning the plug usually means it starts for a bit then dies again. Putting in a new plug it starts up fine and stays running.
I assume this is rich.

Plug: BR8ES
Pilot: 40
Main: 175
Needle: N1EF
Needle Notch: 2 (from top)
Slide: *7
Mix: 50:1 with 95octane and Putoline MX7 (Was running Motul800 but have stopped).

I've checked float height, and that seems to be correct at 16-17mm. I'm at 140m (~500ft). Temps are 5-15C (41-60F) in New Zealand.
Looking through the jetting database, for this bike at these conditions most people seem to be running a richer setup, so I already seem leaner than normal.
I checked the reeds and they seem to be happy. Not letting anything other than a super tiny sliver of light in. A very small chip out of the corner of one of them (see attached).

If I wide open throttle it it usually runs a bit better, but most of my riding is slower technical singletrack. Is this something that I just have to deal with, or can I make it a bit crisper and responsive at the low end?