passme apologies if you've already done so but please make sure you see all the official health test documentation for the parents, particularly the CKCS.
Some of the most devastating and prevalent hereditary health issues in the CKCS can't be reliably avoided just by crossing them to another breed. Even when they're being used for cross breeding it's absolutely vital that the CKCS has had an MRI done to check for any indications of Chiari Malformation/Syringomyelia. The breeder should be happy to show you the official BVA certificate for this test and be able to talk you through the results in terms of what they mean and how they're relevant to their breeding choices.
They should also be following the recommended MVD breeding protocol for the CKCS parent. This means that the CKCS parent should have been at least two and half years old (with no signs of a heart murmur) when they were first bred from and only then as long as both their parents had no signs of heart murmurs by the age of five years.
These are still necessary whatever breed a CKCS is being crossed but particularly when crossing to another breed (such as miniature or toy poodles) where neither condition is unknown.
Obviously these are on top of the necessary annual BVA eye tests (both breeds can suffer from hereditary cataracts and as yet there aren't DNA tests available) and DNA tests for Degenerative Myelopathy and Macrothrombocytopenia (both of which are present in both breeds involved) plus a DNA test for vWD Type I for the poodle parent. Although vWD isn't present in the CKCS so such a cross can't be truly affected it is possible (though rare) for a carrier to become symptomatic to a degree so the test should still be done prior to breeding.
As I said, apologies if you've seen all the certification and it's all fine but breeders of CKCS crosses who actually make use of all the necessary screening schemes are so vanishingly rare I felt it was worth mentioning.