Yes, it is possible to use datomic.ion/cancel with a dev-local DB. Any function on the classpath can be used. However, I think we need a more complete example because you would want to add the function to your ion-config.edn
:allow list as well to support eventually moving said project to a cloud topology. I will take this as an action item to create a full example using datomic.ion/cancel and circle back.