You, HG, have found a case where fast castling is ok because you granted some special blocking power of some pieces towards the otherwise unblockable pieces. That works in those games. But what about 12x12 or 14x14 games that don't have leaping generals? Fast castling is a way to cheap move. I think the player should need to put some work into castling because the gain (king safety) is pretty high.
In variants where the King starts behind multiple rows of pieces, King safety becomes an issue only very late in the game. Unless there are a few jumping pieces and pieces that can block those, which battle on another 'level', where the board is only sparsely populated, and the King is smothered by the normal pieces.
I don't think it would ever be much of a challenge to castle, no matter how many moves it takes to make that possible. The point is that the opponent would have to do it too. E.g. in the case of Shogi, where there is no special castling move, players typically just walk the King to a corner, and surround it with defending pieces, before they even start thinking about attacking. So the major effect of slowing the King's progress towards a safe fortress in the corner is to extend the game with a relatively uninteresting 'prelude'. Depending on your taste you might want to eliminate that, or elevate it to an important strategic decision. I don't see any market for an intermediate case, where you make it just a bit boring and not very important.
In variants where the King starts behind multiple rows of pieces, King safety becomes an issue only very late in the game. Unless there are a few jumping pieces and pieces that can block those, which battle on another 'level', where the board is only sparsely populated, and the King is smothered by the normal pieces.
I don't think it would ever be much of a challenge to castle, no matter how many moves it takes to make that possible. The point is that the opponent would have to do it too. E.g. in the case of Shogi, where there is no special castling move, players typically just walk the King to a corner, and surround it with defending pieces, before they even start thinking about attacking. So the major effect of slowing the King's progress towards a safe fortress in the corner is to extend the game with a relatively uninteresting 'prelude'. Depending on your taste you might want to eliminate that, or elevate it to an important strategic decision. I don't see any market for an intermediate case, where you make it just a bit boring and not very important.