Well, Apache stapling support is better directed at an Apache forum. There has been more discussion about that on this forum given Let's Encrypt's recent announcement: Intent to End OCSP Service - Let's Encrypt
Use this forum's Advanced Search for Must-Staple and look at recent threads
Perhaps also see these for further "food for thought"
https://httpd.apache.org/docs/current/mod/mod_md.html#mdstapleothers