DxOmark tested the Panasonic S1 sensor. And if you were wondering if the S1 uses the same Sony 24 MP sensor used by the Z6 and A7III the answer seems to be clearly yes. DxO writes:

With just one point between them in the DxOMark rankings and similar Portrait, Landscape, and Sports scores, the new Lumix DC-S1 sensor performs practically identically to its most direct competitors.

The overall conclusion:

With the new 24MP Lumix DC-S1, Panasonic has adopted a class-leading sensor for its venture into full-frame. The test results are practically identical to those of the sensor used in the highly-acclaimed Sony A7 III, and in some areas, such as dynamic range, the S1 is able to offer an advantage in the highly desirable ISO 800 to ISO 1600 range, not just at base ISO 100.

It achieves all this while maintaining low noise levels (as we’ve also seen with the Nikon Z6 and the Sony), which demonstrates that 24MP full-frame CMOS BSI-type sensors offer a desirable balance between pixel count and sensor dynamics.

When you combine a high-performing sensor with a proven AF system, built-in stabilization, 9 fps continuous shooting, and a relatively new lens mount backed by influential lens makers, you have a highly capable camera and the beginnings of a promising system that can pose a serious challenge to the top three camera makers.

And this is the Dynamic Range measured by Photonstophotos:

Again, all odds speak for the S1 and A7III using the same sensor!

Links:
Panasonic S1R at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic S1 at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 50mm f/1.4 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 24-105mm f/4.0 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.
Panasonic 70-200mm f/4.0 S at Amazon, Adorama and BHphoto. In Europe at Calumet DE, ParkCameras, Jessops.