Automatically add label "In Review" after arc diff referring to a task

Hello.

My problem is that I have a bunch of bugs to solve, and that I would like to easily distinguish between the ones that have already been solved (and waiting for review but not closed at that moment) and the ones that still need coding.

All the tasks appearing in Maniphest (up to the moment they are closed and striken-through) look the same, and I would like to automate something, for example to automatically add a Label “In Review” to the task.

Herald on Tasks almost works but there is no possibility to select [Revisions and commits] [newly created] in Task Fields. Is there a reason for that?

Maybe I need to delve into Webhooks to solve my problem, but if there is an easy way, I am all ears!

Thanks a lot.