Positioning bifocals in nontraditional positions is common practice in Safety glasses. On several occasions I purchased glasses with the bifocal on top. I had painters who did fine over head work.
I've been recommended by an optometrist to consider a lens style that has a non-corrected planar center and a bifocal area above AND below the center area.
I've asked my eye surgeon via email if that'll work.
But, all suggestions are welcome, and appreciated!