If you control all the clients/browsers (i.e. you can immediately modify the required trust stores), you don't have any use for PKI whatsoever. PKI's use case

If you control all the clients/browsers (i.e. you can immediately modify the required trust stores), you don't have any use for PKI whatsoever. PKI's use case begins with shipping a trust store into the wild, where it will run unchanged for months or years.