I would like to see the "swap" version of 5-in-line at BK. The swap completely takes away 1st player`s advantage and would require only VERY little modifications to the current version.
The swap-version is simply regular 5-in-line with 2. player having an option of choosing whether he wants to play as black or white after total of 3 moves have been made. I personally think that 2nd player`s 1st move should be restricted so that it cannot be made OUTSIDE the same 5x5 center square inside which 1st player`s 2nd move cannot be made in Pente or pro-gomoku. Without this restriction player 2 could make his first move into 1 of the corners and get the advantage to himself.
Even in pro-gomoku the 1. players advantage is very big, but not so with the swap.
I`ll also post this text to the 5-in-line discussion board to get some comments about the restriction for 2. player which I proposed here.

I concider myself a reasonably serious board game player. I am also very busy on most days of the week.
On those busy days I usually don`t play games that require lot of thinking and analysing BUT play a few moves in games in which the next move is obvious and/or easy to come up with.
Some moves are easy and relaxing but some moves can feel like a duty IF you have to make them when you don`t feel like it.
For this reason I have sometimes used the vacation days the way Caissus objected to.