I have all the bits for sale to convert the grille to the non electric version. Consists of the grille (which is already blanked off) the centre bar, and the two infill pieces below the grille.
It should also be noted that the center bar and two infill pieces are for a Mini without parking sensors. If you have parking sensors, you need a different center bar and infill pieces.
BTW, I've done the same conversion on my 2021 SE and love it.