There are a few options for complete oxidation I see:
4 FOOF + 3 CH4 = 2 CF4 + CO2 + 6 H2O (but according to wikipedia, tetrafluoromethane can combust, producing carbonyl fluoride) 4 FOOF + 3 CH4 = 3 COF2 + 2 HF + 5 H2O (but according to wikipedia, carbonyl fluoride is unstable with water)
4 FOOF + 3 CH4 = 3 CO2 + 8 HF + 2 H2O (best single candidate I have)
Disclaimer: I am not a chemist.
Thanks for doing this; adding up reaction products is really difficult for me. I've used the last to avoid having to make loads of dissociation compounds. Other ingame reactions also seem to use such idealised products, so it will be consistent with them that way. In reality you get all sorts of weird trace compounds coming out engines using more than two elements and there's no set 'dissociation recipe' like this. Anyway, I also did a silane reaction since it was a simple enough step at that point.
I've found that hydrofoof engines do produce thrust/velocity between that of hydrolox and fluorolox, too. Maybe my initial screenshots were particular to the engine design I went through the propellants on; in any case I've removed them.
The first reaction is not balanced and the second is impossible because it can't be balanced. I noticed that after Boron Trioxide there is an horizontal tab, so maybe you wanted to add another reaction product but forgot to. Adding water the reaction can be balanced, but I don't know if that is exactly what happens. If it is, then these reactions should be: ChemicalReaction FOOF Hydrogen Reactants Dioxygen Difluoride Hydrogen ReactantCounts 1 3 Products Hydrogen Fluoride Water ProductCounts 2 2 ActivationEnergy_kJ__mol 82.8 AutoignitionTemperature_K 773 CharacteristicLength_m .7747