Because of the Reports.addReport and Reports.filterReports events, reports may be different per website. However, currently, we cache only plugin aware but we need to include idSite(s).
I switched the cache from eager cache to lazy cache as there could be hundreds of sites and putting all this into eager cache would make that cache slow where it actually is supposed to be super fast.
Merging now as patch needed. Let me know if any questions or feedback