I have tried to titrate after stage 1 many times (or as i now call it the enhanced glycerol pre-wash) and it can't be done as the oil is already alkaline. This is exactly what Manfred is saying, and lets face it, if after adding stage 1 chemicals the oil was still acidic there would be something seriously wrong.
Bio Boy, The base amount of catalyst you will need after stage 1 will vary depending on your processor/pump efficiency. From recent tests I have done using the tam 120/eductor I have found my base amount to be around the 6.7/6.8 gms KOH region. Whereas using a processor with a weak pump can give results of over 8 to 10 gms. These figures are without adjusting for KOH being only 90%.
So every processor has it's own base amount. When you calculate the amount of unreacted oil for your stage 2 chemicals you will get to know what the base amount is for your set-up from experiance.
The base amount was calculated years ago by tests using new oil and thats where the 5.0gms NaOH/7.0gmsKOH was first derived from.
Again from recent testing I have done, new oil still titrates, nor is it dry. Maybe thats why my testing figures are below base levels.