I used that once way back when the game was new. I did it just to be able to mess around with all the different techs from the git-go so I could get some experience with how they worked. I have no idea how it might work these days, but I think you'd definitely be able to learn which unique tech tree works best for your play style if you tried a BotG game as each civ.

You have to make separate scenarios for each race - and because you start with Xeno Ethics, I don't think you can actually choose a morality - I seem to recall not being able to build any morality-specific buildings despite having all morality-based techs.