Neither China or Russia has any appetite at present for deeper direct involvement by China.
Given the developments and the general trend that Ukraine and drone warfare has been going, it's best to invest in better air defenses now, and not when Russia has lost a decent chunk of her refineries and oil/gas infrastructure. Unless you think UAV/drone swarms technology is gonna regress and that drones are gonna get more expensive and harder to produce. No of course not, this kind of Ukraine drone swarm strike onto Russia energy infrastructure is just gonna to escalate. It's gonna take some time to set up a Chinese A2/AD too,. It's called foresight and preparation.
I would think China will have the appetite for deeper involvement once Russian oil/gas infrastructure has been decimated, but by then, it would be a little too late wouldn't it?
I noted not long ago that the Russians announced breakthroughs in air defence laser tech. If Silent Hunter style anti air lasers start appearing en mass around Russian refineries and other key strategic infrastructure with a slightly different shell, who’s going to look under the hood to check they are indeed Russian?
The solution should be based on cheap and mass produced mature technology, not Lazers.
1) We're talking about a Cessna-like propeller driven UAV here, not tiny handheld drones, not cruise missiles. WW2 flak cannons should be able to shoot this kinds of aircraft down, let alone modern AA guns. Frankly it's pathetic that this strikes are happening so deep inside Russia, considering that it's basically an unmanned civilian aircraft packed with explosives. Russia SPAAGs, Shilka/Tunguska/Pantsir should all be able to shoot them down easily. I have no idea how swarms of this UAVs are capable to penerating so deep within Russia airspace. I guessing that all modern Russian SPAAG are busy at the frontlines with FPV drones and can't be spared for deployement for defensive positions deep within Russia. Sending in Chinese SPAAGs systems by the dozens is a easy, effective and quick solution.
2) Laser systems like silent hunter are meant mainly for small UAVs like Mavics such, I'm not sure how they would do vs a plane that will weights>1 ton. Also laser systems don't work in the rain, so it will be simple for Ukraine to adapt into launching their UAV during a rainy day. Also, lasers don't still don't too well vs multiple targets- due to time on target and over heating issues, so drone swarms will still get though via sheer weight of numbers.
3) People aren't dumb, if Russia is suddenly fielding an advanced laser weapon when they're not even able to do basic WW2 tier air defense before, of course people are gonna to suspect that China is helping them in some fashion. What next? North Korea develops a 5th gen stealth fighter and people think that NK developed it completely independently and don't suspect that maybe China had something to with it?
4) A cheap and quick solution is the best, it's hard to see even China mass producing silent hunter system in the dozens or even hundreds that it would take to cover most of Russia's critical infrastructure. A simple gun based mounted CWIS system on the other hand...
things are not so straight forwards as there would be almost overwhelming pressure within the Russian military to redeploy such systems directly to the front, which would then introduce the very real risk of these systems being captured by Ukraine
I highly highly doubt that Russians would be that dumb, espically not if China sets some redlines and promises to never set any aid for the rest of the war or some other equally as harsh penalties if they were sent to the frontlines. Also, when given weapons systems, there's no way China just sends the hardware without some kind of techincal support and training staff. They can easily report back to Beijing the status of the hardware and make sure that it isn't send to the frontlines. If all else fails, just slap a GPS tracker on whatever hardware that gets send.