So you need some sort of sealant on the keys? Or maybe just a flame polish?
Then I realized I could just buy two Magic Keyboards and use them at the same time -- typing on the left half of the left one, and the right half of the right one.
After all, the proper ergonomic position is for your forearms to be parallel (not angled inward), which means the keyboard halves you're using should be approximately shoulder-width apart, so there's tons of room to use both without them colliding.
Once I figured it out, I felt like an idiot for not figuring it out a decade earlier. I'm never going back.
Putting the micro-controllers at the far ends means the rest of the board can be lower, meaning less need for palm supports. Also I like you NOT having OLED screens - they're toys at best and one more thing to break at worse.
As for Ortho VS Staggered, ortho has the great advantage of things like WASD just being usable out of the box, and also flexibility with things like numpad layers. I've printed paper cut outs of things like the ferris sweep to see if pinky stagger would be comfortable for me, and the answer was negative. Probably very hand dependent.
Curious why aluminium and not steel? Steel is a heavier, and also has less of that pingy noise, though I have no idea about machining so perhaps it's a no go.
Steel is likely better and surely stronger, but manufacturers charge 2x more for steel alloy machining. At that price level, titanium also becomes an interesting option.
The cost of all the tools and software I did not track but I would guess I invested somewhere around $1K which includes software licenses, shipping, new tools etc.
But I find tracking the cost of research a bit impractical as it doesn't include indirect costs like billable hours that I technically could have spent on clients etc.