ok, directly using a 36V PSU can also Work, but make sure to use some Kind of current Limiter. Those big LED-Chips actually dont care that much about Voltage as they do about current. Each one of the 6 Chanels this Chip has needs exact current to Specification on the Datasheet, if you feed them Fixed Voltage from a big PSU, some or even all of the Chanels can draw more than they should, and that will dramatically lower livespan of the Chip. i think going over by 5-10% in current allready lowers Livespan by a lot. So you need a Dedicated Current Limiting Circut for every one anyways. Nice Thing about those Voltage Boost-Converters i linked is, that they allready have built-in adjustable Current-Limiting. So you can Set every one of those 6 Drivers to the Current your LED Needs (or go 1 to 2% under for Extended Livespan), and use The Voltage control Potentiometer as A dimmer Function. You can Try using the 36V PSU directly, but i personally would be afraid to Damage such a Expensive Chip or lower the Livespan by doing that. If you actually end up doing that, i would at least reccomend you to power each one of the 6 chanels up individually with that PSU and measuring the Current it actually draws, and if its over specified Current, adding a (powerfull enough) Resistor of correct Value in between that chanel and the PSU to make sure, none of the Chanels draws to much and will fail soon because of that.
.
So thats what i would do at least, yours may also work just fine, but i designed mine to work 300% Sure and Really Long term, so i figued a propper Current Limiting Circut would be needed, and because just Heating it away with a Clasic Linear Current Limiting Circut would not only be rather wastefull, but would also create impressive amounts of heat for the kind of Load its supposed to drive, i figured those Step-Up-Driver Boards would be easiest solution.
.
However, if you can get your entire Power Supply Stage done with a single unit and 200$, that has its point of relevance. Still would make sure to at least check the Current, cause its not usually best practice to just put LEDs of any kind in paralell without some kind of current Limiting, even be it done by some Resistors.