That's what I do. I shoot USPSA for the competition and to test/develop my skills and I shoot IDPA to train my EDC.
IDPA has fewer matches than USPSA so it's nice to bring the speed/accuracy to IDPA with your EDC despite some differences in the way the game is played.
I will say however that I do like the gun divisions more in IDPA, but other than that I lean more USPSA.
I was looking forward to trying IDPA for the first time this Sunday at Prado but it looks like the match got cancelled due to low registration. Hopefully that’s not a bad sign for future IDPA matches there