1/ Thoughts on foldable phone sizes:
• The unfolded screen should be wide not square.
• That can be achieved by folding the typical phone size three times or by folding a wider phone once.
• Google originally did the latter and it now seems to be coming back (Samsung and probably Apple).
• The DIN (A4 etc.) aspect ratio is perfect: If you fold it in half, the ratio is the same (Math.SQRT2 in JavaScript).
