Hey I was gonna post in the thread but realized it was way to much to post so I sent some info via PM you can ignore if you wish 
But I got started typing and didn’t realize how much it was.
I think, if I understand your plan correctly, that you want to Self a female. Then cross the S1s to the best male from the original beans you chose the Female to S1 from. Is that right ?
If so I do believe those offspring would just be F1s as you didn’t use the male as a parent to start.
To make a Bx1 you would have needed to use either parent from an original cross and make baby’s with the next generation.
I honestly think you should just choose the best of the best and make F1s. If you want keep the parents, run the line using the best parents you can find and then use an original parent to cross with your F3 or F4 beans to make the Bx1.