What fare price is the current flight where you got that offer? Maybe you should test it again on another flight that is cheaper. Book the flight, get the awards and miles option, then cancel the flight within the 24 hours cancellation (do not buy Basic Economy). Maybe other FTers that have done this can suggest flights that give you a number closer to what you need.

Or when you are doing that last trip that you mentioned you can SDC to flights with a connection to increase the PQM. I don't know your status so don't know if you will get hit with a fee.

Are you located in the US? If yes, will you have the $6,000 PQD? Or have you spent $25,000 on the United Chase credit card?