Toot tooooot! :-))
Looks like some Russky fellows did some investigation concerning the QiHang QH20LP driver. They also love cats. :-)
So, the QH20LP driver at least needs some additional input capacitance to mitigate output ripple.
I recently ordered some more affordable AC drivers from gracelightled. Out of its plastic case this is how the drivers look:
The driver board reads “Dark Energy” at the component free underside. Tested one unit's current output: 0.603A, with a no-load output voltage close to 42V. These are beefier than the QiHang QH20LP driver. 15µF + 10µF = 25µF total electrolytic input capacitance (what the QiHang is missing).