How to detect when I have used some bait

[SnowmanDK]

I am trying to add a tooltip to my fishing pins in Destinations and I have succeeded.
It reads the amount of bait suitable for that particular type of water, and adds it to the pin info.
My problem is, when I have used a bait, then it doesn't update to the new amount when I reopen my map.
Only if I change to another map does it update. That is because it is set to re-read bait info from my bag on map change.

Is there a way to detect I have used a bait, so I can get it to update the numbers left?

I have looked into both fishing events and map events, but can't seem to find any that can be used in this case... Or did I miss something?