And the reason I'm expending effort is because this is important to me. My computer isn't just a tool, it's where I spend a significant portion of my life.
I want Mavericks's beautiful interface in my life. That has inherent value.
What remote exploits are you concerned about in that scenario? Where it would affect 10.9, but not 10.16.
I'm not doubting they exist, but I'm really curious the threat scenario that would apply here, and how likely you think that might be.
A few weeks ago, I pointed out to one of our clients that they are using vulnerable TLS library (with know exploits) on internet facing service.
They scheduled upgrade for service in august next year.
So honestly op running obsolete version of osx is really drop in the bucket.