At what oil saturation point do solvents lose their solvency? .

I'd like to know how minimize the amount of solvent used in soaks. I know that ethanol and iso can mix with the oils almost infinitely.. but at what point does the solvent lose its efficiency and draining it and adding it to fresh material become counterproductive?
The solvent would be used to soak multiple batches of material for a couple hours each of at room temp for a crude oil. Just crude is required nothing fancy so there'll be plant material in there.
There's so many factors like plant material and temp quality of product etc.. has anyone done some experimenting?

It doesn't just stop at a given saturation, it slows down starting with anything dissolved in it. The greater the saturation, the slower it extracts. 30 to 50% is probably the effective level to stop at.

If you don't rinse with fresh alcohol, the solvent that you leave behind in the spent material will also be at that saturation.

I'll extend the soak time for each additional load of fresh material and give all of the spent product a final rinse with fresh solvent and run it through a screw press one more time. I'll do some testing with running it through the press without a fresh solvent rinse as well as the press gets quite a bit out.

Thanks for the info.. I'll let you know how my experiments go.