I played the first case with three players and I enjoyed it, but it was somewhat lacking since as predicted the players didn't feel the need to block or get in each other's way.
It's my only gripe with the game and the reason I'm not playing it as much as I would want. I wish the designer would put the time and work a viable variant. With 3 or less, there just isn't a reason to block and with that goes away a big part of the game.
Good luck with your variant Jude!