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So the diamond hotend setup looks fine to me, and while I think you'll get that laser to work it's a tight fit with the piezo tensioning bolts.
I might recommend for the laser that you mount it to the piezo plate.stl object directly since presumably you don't need to use the leveling features here of the piezo disc. EVen if you are looking to swap tools from time to time, I find that removing the whole piezo plate setup to be a breeze. You'll need to disconnect the piezo from the PCB, but this way you keep the pretensioning on the disc and it's 3 easy access bolts from that point.
Does that make sense?