ReShade does not have any keybindings apart from the screenshot key. All other key bindings can be defined by the shader authors, so you cannot toggle with just spacebar, that's what MasterEffect is doing, but that's not how it has to be done. Yes, of course ReShade allows to toggle each effect on its own, but that has to be implemented by the shader author, in your case Marty McFly.
There don't seem to be virtual keycode definitions for the XBOX controller, that one needs to be handled via a separate API (XInput), which is not currently planned. I'll put it on the TODO list for future things though
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