> Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it.

I can see how you would end up in that position

You need to add constraints to your sketches. In other words tell it that the hole needs to be x distance from certain lines.

If you don't do that what you get is the equivalent of hard coding a hole location in OpenSCAD. I guess OpenSCAD just forces you to think parametrically.

Also in fusion 360 make sure timeline editing is on.