I love the vertical format of the original holder, and wanted to incorporate it into my gridfinity system. 

My goal was to use the smallest grid section possible, which is 1x7.

I trimmed the ends of the outer blocks so it can be printed diagonally on my Prusa MK3S+ (or any of the i3 models)

It takes common 6x2mm magnets, if you want extra stability, but it works well even without them.

I printed in PETG, with a .6 nozzle and .35 layer height. 15% gyroid infill. 2 perimiters, no supports. It is just under 4 hours to print. (The magnet holes needed a little cleanup with these settings.)