i'm using Custom vision from Microsoft service to classify image. Since the model will have to be re train few times a years, I would like to know if I can save current version of azure custom vision model to re train my new model on the same version? because I guess microsoft will try to increase performances of its service among time so model used on this tools will probably change...
You can export the model after each run, but you cannot use an existing model as a starting point for another training run. So yes, as it is a managed service, Microsoft might optimize or somehow change the algorithms to train in the background. It is on you to decide if that works for you. If not, a managed service like this is probably generally not something you should use, but instead train your own models entirely.