Has anyone experimented or tried a vertical entrance on the underside of a bottom board? And if you have, what was your experience? How well did the bees enter into the hive this way? Thanks!

I was thinking about how to improve the KTBH design so I built 3 small ones out of poplar measuring 19" x 19" by 10" tall with a 1" left entrance in each. Made the base 19" x 19" x 3/4" plywood so that they can be stacked and drilled six 1" holes so that bees can move up and down. Basically...