Tax Config Vendor then Flexfield

Hello, I need a prod in the right direction with this please

I have managed to do some low level config in:

Tax Determing Facctor Sets

Tax Condition Sets

Tax Rules

to get a get a Seg3 of our CoA to declare a specifc Recovery Rate

My next task is to try to get Vendor = XXX & COA Seg3 = ZZZ to declare a different Tax Classification Code than what it would based on the supplier setup

Can anyone point me in the right direction?

I seem to find, looking on MOS there are a lot of (maybe too many) notes

I guess this is just a function of configurability of the EBTax product