Tool for importing pre-existing appointments from other booking systems

As a merchant, I may have pre-existing bookings from another system we used. Since the Experiences app currently requires that each new experience is first created in Experiences, which is then created as a Shopify product, this isn't possible and creates problems for legacy bookings from other systems. I'd like to be able to import legacy bookings into the Experiences system so these guests and my business have no interruption. - I should be able to choose whether or not the imported customers get the initial confirmation emails (and other emails) - I must be able to import them without having to take payment - If I import a booking for which there is no time slot, I should be warned somehow - I should be able to match up my pre-existing customers into the Experiences system. Much like how MailChimp allows you to import an email list.