He ordered it direct from a dealer in China that makes router bits and spiral cutter heads to spec. It's absolutely superb quality, and was only $225 AUD landed which I thought was a bargain. Aliexpress does have similar cheaper ones but they aren't quite as good quality I think:
https://www.aliexpress.com/item/1005002122884352.html?spm=a2g0o.cart.0.0.1bf838daBqWvvM&mp=1
The flutes are noticeably different, but I don't see why they wouldn't be very good despite being cheaper, I'll be buying a few from Ali to try out. The fact you can use all 4 edges of the inserts is just great, in comparison my thicknesser only has 2 usable edges.
I did initially really worry about the sheer mass and size of it with the router, but needn't have worried. I trimmed roughly 5-8mm off a bunch of 30mm thick hard maple architrave edges in one pass, and it was whisper quiet in use, no kickback or vibration of any kind, just super smooth! Had the speed set to 3-4 on the OF2200.
I'll try and find out the details of the guy he went through.