Got it. I lucked out and SJC-BUR was also $49 that day. I switched the 2nd pair to that, so I'll be doing SJC-LAX-SJC-BUR-SJC instead now. Luckily there's a lot of flights each way that day so if there's a delay on any one segment I'll be covered. They're all individually booked so I do have to worry about no-shows if I get any serious delays, but I suspect I can handle that between the app and the gate agents (plus delays tend to be rare on those routes).
I'll end up with 94 planned segments this year, so I'd decided to go for CP if I could do it cheaply enough.