(1) Can you refresh from a PROD Environment which is 15.2 to a Dev environment which is 15.4?
(2) Also, can you exclude any custom objects from the source environment in a refresh?
Release: CODFSS99000-15.4.1-PPM SAAS FedRAMP-Sandbox-Small Environment
(1) In general, we cannot refresh a target environment using data from a source environment which is at a lower release of CA PPM because there are differences in the DB schema design between major releases.
(2) It is not possible to exclude custom objects stored in the source environment database because it contains all of the OOTB and custom objects; a refresh copies all of the data from the source environment to the target environment so they are identical.