BTW - congrats on passing your CCSP and welcome to the club!
My view is you should be selective when submitting your CPEs. If the educational content covered domains from both CISSP and CCSP then apply the CPE(s) to both. If it just covered domains from one certificate then just apply it to the appropriate one.
That being said, it was a rare occurrence when I submitted CPEs that were not applicable to both CISSP and CCSP. Also, any CPEs that are auto-submitted will be applied to all of your certifications regardless if they were applicable to all or not.
