Hi all! I'm sharing this object that I use to easily switch engines when working between different gl2/gl3 projects. You simply add the object [gl.check] to your patcher and add the argument gl2 or gl3 (default is gl3) so it will check what engine is used when starting the patcher. If the engine does not match the engine of the argument it will prompt you with the question if you want to switch. When clicking OK you get the prompt to restart Max (as you normally would when switching the engines through the preferences). You can also transform it to a [bpatcher] to use a umenu to manually switch from within your patch.

https://github.com/tmhglnd/gl.check