New menus when creating variant boards

I think there should be a menu when creating a new variants chess board; the ability to have a piece in the center of a (let's say, 5x5 grid) and you could click some squares and those would be the squares the piece could move to.

Alternatively, a menu to combine and subtract pieces from each other could also be nice, e.g. combine a horse and a camel for a wildebeest.

I do understand that there could be some difficulties with implementing this, such as ambbiguity about what some pieces do. But it might be interesting to play around with.

Also, a new menu for promoting pieces other than pawns could be very interesting too. I feel that a drop-down to choose what some pieces could promote to and where could be used in some very interesting setups.

I know this is quite vague, but these features would be cool to have.

Cheers!

noice