Thanks for posting this and including pictures of the PCB. It really does look like it is derived from my design. Sadly they cut out about $2 of components which impact performance and make this a pretty bad implementation. Penny wise pound foolish.
I built mine because I was frustrated there was no low-cost mini probe. So it's nice to see China follow up and make one, I consider the copy a badge of honor

.However, I am not pleased with the quality of this implementation, they cut so many corners. I might just have to buy one though. It would be funny to own a copy of something I designed.
Some Complaints:
All the protection components were removed, even the PCB spark gaps and fusable traces. Given how thin the insulation on the coil is, this is a serious safety risk.
The probe has horrible flatness with peaking at low frequency and at high frequency and a jump in gain on the transition from the active integrator to passive integrator. They removed all the adjustable components and it seems like they changed the coil properties without changing other important component values.
TopQuark, if you are interested in taking any more measurements:
What does the coil look/feel like? I spend hundreds of dollars on trying different heat shrink out for the coil and it looks like they used polyolefin heat shrink (the generic type of heat shrink used in most applications), which I had ruled out. Compared to the FEP heatshrink I used, polyolefin heat has a lower breakdown voltage, is more easily abraded, and is less heat resistant. All important factors when you are running this probe close to high power electronics that can get hot / have high dV/dt.
Whats the interference rejection look like? Try putting your cellphone a few inches from the coil or the amplifier and running an internet speed test while on WiFi or LTE. There will probably be volt+ spikes on the output. On my design the capacitance for the passive integrator on the input is distributed with careful layout to reject EMI coupled into the cable and coil and I used a small ferrite bead common mode choke on the input cable in conjunction with a shielded case. This design has none of those features.
Its hard to tell from your measurements, whats the RMS and P-P noise? As you said, it does look like they are using a X7R or similar capacitor for the servo highpass filter, which could couple in noise. But it also seems like the lower frequency cutoff is higher. Either way I am curious how the noise level compares to my probe.