Will Cross Processing Ruin my C-41 Chemicals?

I have 1000mL of Unicolor C-41 chemistry mixed up and ready to go. If I use 200mL of solution to process one roll of c-41 and one roll of e-6 in the same batch and put the 200mL back into the container (I need the full 1000mL for some processes) will it ruin my c-41 chemicals? The chemicals are pretty fresh and this is the first time cross processing with this batch of chemicals.

My local pro photo lab never bats an eye about cross processing, they say it does not affect their C-41 chemicals

No, it will not.

PE