The laser cutter’s natty little diode on the focus head has always been a bit of a useless tool. That was right before I broke it, when I replaced the old PSU with a new one that doesn’t provide 5v.
Sitting at home is a proper 5v DIN rail supply ready to be fitted to rejuvenate this functionality - but what kind of hackspace would we be if we passed up the opportunity to make it better?
Enter the addition of two additional diode modules:
Not only will it provide more accurate sighting of centres, but also the ability to focus the laser without use of the gauge. 
I have all the materials required on the way to fit this when I return.