I have been also working on a far more stable entrance slit design and decided to include it with the build instructions. I have tested it several times and will post my results, I made one for my 0.12mm slit and my 0.09mm slit.
The slit I am using now is the 0.09mm one.
http://publiclab.org/notes/dhaffnersr/08-11-2016/complete-redesign-of-entrance-slit
Thanks Dave H