suggestion, drill a 10.7mm hole and screw track (thread ?) it with the same track and step of the aixiz module.
Then you can screw the module on the heatsink, maybe using a bit of thermal grease on the screw track too ..... robust assembly, decent heat transfer ..... and you don't need to drill a lateral m3 hole and screw track it for fix the module in the 12mm hole too
Try getting the cheapest heatsink you can find, most are made with an easily drillable copper central column. For example the stock Intel heatsink, that's almost free. Just ask in a computer store whether they have any surplus. Plus, you get thermal grease with them
Try this way: take a spare old AMD heatsink, the ones with an 80mm fan and a good thickness of aluminium on the cpu side ..... then take a cube of aluminium, work it with a 12mm hole for the module, and glue it on the cpu side with thermal glue, or fix it there in the way you prefer, and you have a decent cooler with also the space for the current regulator on it.
If you want to complicate yourself your life , you can also do like i made my first lab-style one, and work it with keeping screws and so on, like in the pic (mine have 2 holding holes and 2 regulators, one fixed and one variable, but that was a personal choice due to the need of the moment)
BTW, my cube holder (that is anything except a "cube" LOL) look a bit bad done, but is just cause i don't have any machine at home, just drill, and hand tools, and had to build it all handy ..... if you have some machine, or the possibility to ask someone, better you work it with machines, also for the aspect
If so, let me post some more images, so you can have a better idea about how i made it, and then you can build yourself also better
BTW, if you want to do it as a 2 places like mine, better that you use an aluminium block a little more large than mine, i used this size just cause i had only this, at the moment ..... and you can do the regulators both trimmer-variables, not one fixed with external resistor like mine, i made this way cause i needed it this way.
If you instead decide for a single host, you have all the space you want also for the rest of the circuits, as example, if you want to make also a regulator for fan speed ..... i just regulated it at the speed i wanted with those diodes solded on-the-fly and glued to the heatsink.
Another idea that i had, but never had the time to do it, is put a fixed thermometer on the assembly ..... i always say myself "i have to do it, one day or another", then i always forgot to do it, and still use an external module, LOL!
And, last, i used 4 little silicone self-adhesive feet, for keep the fan spaced from the desk and left the air circulate (yes, the fan is also the base of all )