A minor quibble here about board size: it can be considered a mutator. There are variants which propose placing an 8x8 standard chess set-up in the middle of a 10x10 or 12x12 board. This does change the game a fair bit. Now, with a 10x8, you can use it a few ways. You might have a file a rook can step to on either side of the standard 8x8 set-up, or you could 'play the long way' and set up with 6 rows of 8 squares empty between the 2 sides, or even move both sides up 1 square, so they ar the standard distance apart, but there is an extra row behind each side. Circular boards have long been used, also, for example. But what you are really doing here is examining how board geometry affects play and affects the utility of various pieces (eg: on a Byzantine circular board, bishops are nerfed and rooks are enhanced. In other words, you're playing Chess with Different Boards.
A minor quibble here about board size: it can be considered a mutator. There are variants which propose placing an 8x8 standard chess set-up in the middle of a 10x10 or 12x12 board. This does change the game a fair bit. Now, with a 10x8, you can use it a few ways. You might have a file a rook can step to on either side of the standard 8x8 set-up, or you could 'play the long way' and set up with 6 rows of 8 squares empty between the 2 sides, or even move both sides up 1 square, so they ar the standard distance apart, but there is an extra row behind each side. Circular boards have long been used, also, for example. But what you are really doing here is examining how board geometry affects play and affects the utility of various pieces (eg: on a Byzantine circular board, bishops are nerfed and rooks are enhanced. In other words, you're playing Chess with Different Boards.