rollerce:
I was thinking the 1750 unit would be able to comfortably power all six bars in a 3x3 series-parallel circuit
Never run LEDs in parallel like you're suggesting. Each LED needs its own current limiting circuit.
If LED "A" has a Vf of 12V and the parallel-wired LED "B", due to manufacturing tolerances, has a Vf of 11.8V then LED B will suck up more current than LED A. Eventually it burns out, then all the current flows through LED A and that burns out and on down the line.
What you should be looking for is something like this LED driver, but of course you need to find one that matches the current requirements of your LEDs. If you read the datasheet on the XLSemi XL6001 you'll find that the three resistors (R1, R2, R3) set the maximum current and it would be possible to replace them to set the limit you need, but of course it'd be a lot simpler just to get one pre-made.