A: Short answer is Generally Not.
Longer answer – Having the kiosks staffed is taking the “self” out of “self-service”. But if the kiosk are staffed, or at least sufficiently staffed so that everyone has good opportunity to get help, a business is probably at low risk with such an approach. Assuming that only people with disabilities need the option of having a person assist them is a high risk approach (in our opinion), and (to the best of our knowledge) not at all well supported by case law.
Where the regulations do have clear requirements for self-service kiosks (i.e.: kiosks under 508, ATMs and fare vending machines under ADA, and airline ticketing kiosks under ACAA), personal assistance is not permitted as a substitute for conformance with the accessibility requirements.