One of our markets is planning for an upcoming fund-raising event with a local non-profit (CRA-eligible organization) for which our bank is planning to be a key sponsor in addition to supporting with employee volunteers.

For the sponsorship we plan to get a receipt or other tax-compliant acknowledgement from the organization identifying portion of our sponsorship qualifying as a donation separate from value for "goods/services" received as part of the sponsorship and use that to support CRA-credit for that portion of the donation.

Available volunteer activities are being separated between initial set up prior to the event (employees can sign up to help set up tables, decorate, and other prep) and cahier activities during the event (volunteers sell tickets take donations, other "cash-handling" activities). My understanding is that only the cashier activities would be eligible for CRA service credit (i.e. financial service/job-related activity) vs. the general set up/prep, even though the organization and event overall qualifies for CRA, is that correct?

I agree with your understanding.