DD’s experience was even talking to students and advisors of the same school, there were different opinions about this. She ended up taking old math exams that were posted by her math department and deciding for herself with the approval of her advisor. She skipped into calc II but added an extra recitation and did fine. She probably could have started in calc III, which she is finding easier than II, but YMMV depending on the school.
If your student doesn’t need any Chem, use the credit and be done. If it means he’ll need a higher level chem class instead, I would not skip.