Hi Justin Molenaur ,
I forgot to answer the other question: yes, it is ok not to have a difference on the min(last_execution_timestamp) of m_sql_plan_cache and host_sql_plan_cache.
I'd guess you tested that on a fairly new system and there isn't much going on there in terms of sql plan cache usage and that's probably reflecting on the historic data. Once cache evictions start happening then you should start seeing a difference between those.
Here's what it looks like on one of the systems I have access to:
BRs,
Lucas de Oliveira