I can't work out what the event is that I need to hook into to catch changes to custom fields. I assumed the render.done event was what I needed but after debugging I can see it's not.
Basically, I need to dynamically update my Terms Of Service link with parameters that include the latest cart prices and quantities as well as my custom fields. I have no problem adding parameters to the TOS URL, it's just my custom fields that are a problem. When I enter the custom field details I can't get them to get added as parameters to the TOS URL.
So what event do I need to catch any changes to custom fields?