Our FR5 packing quote leaves fixture acceptance with the person buying it

I can see who designs and makes the presentation fixture in each offer, but neither says who demonstrates acceptance with our packaged connector kits. One supplier describes that work as customer commissioning. I have added a separate allowance for the trial, our operator time and any fixture revisions it exposes. The equipment total looked settled only because this part of the job had no owner. Has anyone used a provisional acceptance allowance without letting it turn into an unlimited obligation?