Good for you! That is quite the accomplishment. I was training to do this back in 1994 when I was dianosed with cervical/uterine cancer. Such is life.
That many hours on a bike can get uncomfortable. In many ways.
That is a lot of stitches on the needle and with the beads, definitely not a quick process.
Can it ever get uncomfortable- that is why I sewed myself a padded seat cover from some genuine sheep skin I had. Made a huge difference. I found the seat on the stationary bike so uncomfortable, plus I had such difficulty getting my leg over the bulk of the mechanism it has gone to the Hospice Shop. The plan is to invest in a sort of free standing cycle mechanism, that you can put in front of your comfy chair- and peddle that.