I must have seen your post before you edited it and IIRC it mentioned how to determine where your module is focused… 
Anyway, hopefully your Neje kit included a little PWM module… I’ve gotten several of them with my several orders from Neje
I lay the laser module down flat on the worksurface, connected to the PWM module (it reads 001, photo timing drops one digit), and +12V power… that’s all that’s needed. I use a wooden block and ruler and slide the laser module back and forth to quickly find focus…
too far…
too close…
just about right!
Get your measurement from bottom of housing to the wooden block or make any focus adjustments… and then go make a gauge block (or step-gauge) to enable setting the proper height when mounted on your machine!
– David