One thing that helps you is you bought the small diameter sensor, I'll bet. Did you print it smaller than .2 layer height? Just curious. I've got an idea or two to try. One is to make it bigger in diameter IS and OS, and printing a threaded sleeve to glue in. Such a sleeve will print in 20 minutes so no biggy. And I can just glue it in the bigger hole.
I got my case feeder mounted, and it's going to drop straight down to the case feeder shuttle, and I'm not terribly high above it, so I want my proximity sensor housing just as short as possible.....NEXT PRINT I may add the fillet....beats all the clean up....no wonder TylerR hates supports..... Still have much more to print.....plate, electronics box, better proximity housing.....but it's going to be cool!
I use RCBS's rifle tube bullet feeder which come with an "M" style die to expand the neck. It has a second 1/16" deep step that captures the bullet and sits it vertical for the merry-go-round to the seating station. You can get similar ones from Lyman or Noe. That means I can take the pull expander out of the sizer, and that helps with concentricity a lot. I also have one for .223.
If you print your feeder dies you could just order a Noe or Lyman M expander and do the same thing.