It would take a little effort, but Tasker can be set up to manipulate all three display values, the bottom display being PF. And Tasker has a built-in function to write to a file on the android phone. So, you would be logging, A, V, PF values probably every second or two. Of course you can log less often. Again, it is not as easy or straight forward like built-in features for the app and most people don’t want to put forth the time or effort, but I just point it out in case someone reads this and wants to try.
I am just a user. Not associated with Mooshim Engineering, Tasker, or any related venture. —Duane