Mileage Run Discussion - UA MR SFO/SJC/OAK to SAN

I'm looking to do a quasi MR on United starting in SFO and ending in San Diego. It's pretty easy to throw in a LAX connection, and maybe even a LAS connection, which @ 500 minimum and doubled isn't bad. But I'd like to dramatically increase the EQM on this if possible by a more creative routing. I'm looking to leave the 30th or 31st of Oct and return Nov 1st or 2nd. Any suggestions greatly appreciated.
I do need to be in San Deigo for halloween but that's about my only constraint.
Any ideas anyone? I tend to only do transcons for miles so this is new to me.

You can try squeezing in MRY or BFL. The number of flights through those two are limited so it'll increase your travel time by a lot, but if you're only looking to maximize miles, they're good options.

Another possibility would be to go SFO- XXX - SAN in one ticket, making the XX something far towards the east, and buying the ruturn from SAN seperately. thoughts? Im trying to do this in leui of a transcon.

Go to Orlando/Tampa on the way to/from SAN.

Often you can find routings like SFO-SBA-LAX-SAN.