Lacquer flame retardant sodium polyborate

I think that soufa can be used to make lacquer flame-retardant.

Is lacquer … difficult?
I think that the soufa solution will repel after lacquer coating, so it may be necessary to mix it with lacquer when constructing.
If so, do they mix in aqueous solution? Or do you mix powder type?

I do not know a little, but I think there is a possibility.