Hello, 92024, there is an alternate worldview…don’t pay ahead and don’t refinance, just keep going with your original mortgage. If you find one day that the value of your house has declined substantially, in California you can just walk away. It’ll bomb your FICO but if you buy another house first, it may not matter to you.
I make no claims for the effect on your karma.
My sister and hubbie got out of SD just before the price declines of the early 90’s knocked their house value down about 30%. As of a couple years ago, it zillowed for 500.
OTOH I built a house in a reasonable suburb of Indianapolis (Lawrence North area) in 1986, for 96k. It’s now worth about 130k. That’s 1.4% a year appreciation for 22 years. Such is life.