Flowing filler OFS 543 - second layer possible?

Hi,
the floor leveling using the above-mentioned self-leveling compound unfortunately did not turn out 100%, there is a stubborn hump remaining. I would now like to sand this down and apply a new layer of self-leveling compound.

Now my question:
Is this possible without any problems?
I assume that I need to apply a primer to the sanded area as well as to the already installed self-leveling compound beforehand, right?

Regards and thanks,
Holger

For multi-layer construction, apply Sopro bonding emulsion beforehand. The substrate must be completely dry in any case.