I'm in the exact same dillema. Just so confused how they have this documentation on the transaction webhooks, but you can't specifically choose to listen to those events and you can others. Did you ever figure this out?

I'm hoping you don't have to subscribe for transaction notifications and you'll just receive them. I'll see tonight as I have transactions who should settle.

I also found this similar issue where support seemed to say that it's so unlikely for it to not settle that they don't have webhook notification for it. This was 8 years ago and again seems very odd with financial transactions.

Also, there are other plenty of other webhook events missing from the possible list of events to listen to.