Update to my original post...

I've finally managed to get a pretty good result. At the end of the day:

1/3 2/3 ratio of platinum to palladium (I started with 50/50)
2/3 1/3 ratio of Ferric Oxalate solution 1 to the restrained solution 2 (again I started at 50/50)
48 drops for an 8x10
I use a rod, then brush out the last puddle.
warming the pt/pd also helps
A big change was aggressively humidifying the Platine over a steam bath and then letting it rest for a few minutes- this cut my exposure time by 1/3, but necessitated constructing a new curve.

Good thing too, I've just about run out of my first batch of chemicals.

Took me 44 tries to get to where I was satisfied, but in fairness that includes a bit of a goof at the beginning when I was printing on the wrong site of the Platine (I didn't notice the watermark till after a few prints) and a few other dead ends.

Anyway I'm hooked. The downside is that now my inkjets look cold and lifeless - almost like trying to sculpt a figure with a meccano set.