Solution found 😊  not using events but rather a simple poseraddon, with something like this in the __init__.,py

class MyClass(poseraddon.Addon, poseraddon.SceneObserver, poseraddon.SceneDataSaver, poseraddon.PrefsSaver):
    def __init__(self):
        self.addonInfo = {
            'id': 'com..my.addon',
            'author': 'me',
            'copyright': '(c) 2022 me',
            'name': "My addon",
            'version': '1.0',
            'observer': 1,
            'scenedata': 1,
        }

    def load(self):
        # load your stuff

    def unload(self):
        # unload your stuff

    def sceneDeleting(self, scene):
        # unload your stuff

    def sceneCreated(self, scene):
        # load your stuff

𝒫𝒽𝓎𝓁

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