I think it’s fair to say that Mick considers those more tweaks than anything else. I also understand his reasoning behind not wanting to change the sound of his product. He knows and understands how his products sound. When you make things sound different he doesn’t know what the end result will be. And to be fair, you don’t either! Lol. Once you get a feel for the sound you can always tweak it later on
When I talk about customizing I’m talking about functional differences as opposed to circuit or design changes. Appearance, tube voltages, outputs, inputs, etc.