gain in early planning 8,8 to 10,0 for 82 cm slalom board

[MacTS]

Hi,

Sorry for a non-starboard related question on this forum.....

I have a 135 L 82 cm width as my biggest slalom board. I have 8,8 as biggest sail for it and a 49 cm fin.
In the summer where i live we often have quite light wind and it is often that the 8,8 feel just a little bit to small.
I wonder if I would gain a lot of early planning potential by adding a 9,8-10,0 sail and of course a bigger fin?

My weight is appr 98-100 kg and I compete on national level in slalom as well as some local competitions.