COB LED Dimming via Poentiometer?
I'd recommend you 86 the 12V power supply and boost driver.

Use a $40 Mean Well HLG-150H-36 CC Driver.  It has a pair of DIM wires where you connect a 100K pot to set the current.  I use 10 resistors and a jumper to select the current.  

I have to question your use of the CXB3590. 


The typical forward voltage is 38.5V @ 3.6 Amp.
Running it at 3.6 Amp makes thermal management very difficult.


I would only use a CoB if size is an issue.  If you were to use some $4 1200 lumen Bridgelux EB Series Gen 2 strips you will get a much better lumens per watt ratio and thermal management would not be needed. Cost would be less per lumen but would take up about a sq. ft. of real estate strips are 11" x 1". Light uniformity would be better with the strips.

The max lm/W for the CXB3590 is 145 lm/W. The strips are 180-175 lm/W.
Heatsinks and fan for the CXB3590 will add considerable cost.  The CBX3590 will also loose efficiency if you do not keep the temperature down.