What shim you use for Sabfoil with Takuma board. It is strange feeling to ride with nose down. I wonder if this position makes harder to get up on foil?

Nose down from the start surely is harder to get up.

I recently made a pretty thin shim (1.5mm - 0) for my GoFoil to Gong board and the extra tuning options it gives you are fantastic, start small and experiment. Usually slightly nose down will give more lift and slightly nose up will give more ride stability at speed.