I'm a bit heavier than you at 100kg and I generally ride a 130 but I did have a 96cm board for a month which was a lot of fun. The thing was I ended up back on the 130 and found that it was far easier to keep progressing and learning new tricks because you can make a mistake and keep riding. On a small pocket if you touch down, 95% of the time you are probably toast. Having said this I am now trying out a 110cm for a while because I'm keen to see what it has to offer (for me I think it will be good for strapless airs due to the light weight and less swing weight).
Conditions also play a part, if you ride in flatter water, a small board is easier to get away with. And what foil you ride and the style of riding - if you are on a bigger foil, and like a more cruisey carvey style, with smaller kites and less power then that can suit smaller boards. Like riding powered up then maybe less so.
Finally, where are you with your foiling and what do you want to get to? If you can do most of what you want and enjoy riding around doing what you do then a shorter board should be fine. But if you are yet to learn some of the core techniques like foot changes or tacks etc then a smaller board will probably slow down your progression to some degree, again that kind of depends on the individual too. You have to decide what balance you want between those aspects of learning and just having fun!
That's just my view on it all, others will swear blindly that its 100cm max or die, each to their own
End of the day, you can always give it a go and if you don't like it, sell it and try again!