Definitely a different board revision than mine but looks like it’s not a problem so long as the current is down to a safe level and the voltage is set before you start the current adjustment. Might have to revise the write-up to include your board version. I’ve run my driver for hours at a time and have never done anything special to cool it down. It’s rated to 3amps and we’re running under 2 so I guess it’s not an issue but a fan wouldn’t hurt either. The diode itself definitely needs a heatsink and a fan though.
I’ve found that the lens has to be unscrewed quite a bit to focus , even at 55mm. I have Teflon tape on my lens screw threads so it doesn’t move once I have it set. I start by setting the height of the heatsink at 55mm and then turn on the laser at the lowest possible power S1 to S3 will usually turn it on. At that power level I’ve adjusted the focus ring without ever burning my fingers. A big adjustment ring would make it easier though. I could screw my lens in further and focus at a farther distance but I’m sure there’s a trade-off in beam power as the distance increases. You also don’t want to be so close that the smoke from the material will foul the lens either.