partition-core shouldn't contain SPI implementations
PartitionServiceImplCache is implemented in the core module: https://community.opengroup.org/osdu/platform/system/partition/-/blob/master/partition-core/src/main/java/org/opengroup/osdu/partition/service/CachedPartitionServiceImpl.java
Partition-core shouldn't contain SPI implementations. SPI should be implemented in CSPs.
Also, it makes some problems within CSP if it needs to use some special logic or even if it doesn't need cache at all: https://community.opengroup.org/osdu/platform/system/partition/-/blob/master/provider/partition-aws/src/main/java/org/opengroup/osdu/partition/provider/aws/service/PartitionServiceDummyListCacheImpl.java#L24
CachedPartitionServiceImpl doesn't contain any complicated logic so it could be combined with PartitionServiceImpl within providers modules or even be removed for ones that don't need it.