Does China sell/license/supply their GFW tech to anyone? Sandvine seems to sell to anyone that tear gas fabricators will sell to (Oh, you'll use this against your own citizens and that's legal because you wrote the law? Great, just check this box!).

"why not blame all possible parties?"

10 years ago I would have said 'it's probably Western companies helping them'.

Now, I would say probably it's Chinese. Frankly, because it's going to be so, so much cheaper, let alone it probably doesn't come with any potential political headaches, and, they are developing a 'core competency' in this.

That said, Putin has serious geopolitical interest in Belarus, and himself is supportive of the regime. Since the Russian state is also 'good at that stuff' it could very well be a state-sponsored initiative.

Finally, Belarus is not Venezuela, wherein they might have difficulty recruiting all the talent necessary to do this. Belarus has enough native talent to contemplate the task.

But it'd be interesting to know 'who' is helping them do this.

Frankly, I don't see why it matters who is selling or managing the equipment. It's a pointless debate that misses the forest for the trees. Only children thought refusing to produce and export this kind of expertise would stop it from from proliferating. The demand and the money aren't going to go away because anyone in particular took the high road. Refusing to participate just means someone else gets the money.