Can I change the B-frame settings after I've already done the first pass?

Is it ok to change the BVOP settings (number of frames, ratio, offset) after the first pass or do I need to run the first pass again? Thanks in advance.

During the second pass, the first pass frame type for the respective frame will be forced. I hope that answers your question. Regards Koepi

Interesting. So basically all the configuration options are ignored for the 2nd pass and take their values from the stats file?

nope. it's about the frame type - the decision is only done on first pass.