Ive noticed that progress towards your shots on goal does progress on the tracker during exhibition games, if you have a second controller load up a 1v1 with no bots and just take shots on goal on the second players net.
The best match parameters seem to be 1v1, unlimited score, and 10+ minutes. This will take several hours of grinding, but is doable in an evening, or one long sitting, i am currently averaging about 90-100 an hour.
Progress does not seem to be counted from shots on goal prior to this update, and is not stackable with certified items during exhibition.
UPDATE 07/10/16: if the tracker is getting stuck at 98%-99% for like it has been for some folks, a helpful user has left a suggestion in the comments that may help, several users and myself have had success with this:
"Mine got stuck at 98% as well. I switched my profile to an alternate one on the games main menu, then switched back to my main. After which the progress tracker worked again after doing more shots."
UPDATE 11/10/16: my tracker was stuck at 99%, what worked for me was signing into another profile, scoring a goal (which unlocked an achievement for that profile), switching back to my profile and loading up the game.
Any questions or additional suggestions feel free to send me a message and i will see if i can help.