Paperw8
The input capacitance MUST be 220pf because I used to use an MM cartridge on my PS.30R. MM cartridges require capacitance as you know, that's why they are there. dropping the 220pf and you'll have a really crappy sound on MM. I know because I took out my 220pf from my older PS.20 loading plugs and the sound was like a cheap 1920's gramophone.
MC cartridges don't really need capacitance but resistor loading. There is a big debate out there about required capacitance for MC. I have a friend who is an avid DIYer and he increased the input capacitance of his homebrew stage from 200pf to 1nf in 5 steps while using an old Linn Troika. Nothing really happened. But changing the load from 100ohms to 1k ohms in 5 steps made a massive difference at every step.
Also if you check inside the Whest 30R you will see 2 polypropylene 220pf capacitors at the RCA connectors. I think you may be doing the wrong thing or just totally forgotten 4th grade science.
I sort of remember in school physics that measuring resistance in parallel with capacitance will give you the reactance or a reactance measurement but trying to measure correct capacitance with a resistor across it is pretty hard if not impossible.
How do you measure the capacitance of your tonearm cable??? You must have to load it with a fixed resistor, measure the reactance and do the math to get the capacitance value.
I have found that loading does affect dynamics and presentation but needs to be set for the system and room. There are no hard fast rules with loading as moving the whole system to another room may need a different lading system because of the room.