I use blanks for certain things. I prefer blanking the bigs over guards but mainly use it when I am one position training. Blanking positions seems to tend to favor the better offensive player but it does a good job of managing stamina throughout the game.
For training one spot, it helps eliminate those last minute substitutions for your trainee. Just helps get the full 48 minutes.
Blank the starting spot. Then list your trainee for backup and reserve. Set the other positions as you would normally. Play strictly follow depth chart and it does a good job.