Screenshot as PNG instead of JPEG? Is there a way to teach a Samsung Galaxy S9+ with Android 9 (Pie) to generate screenshots as PNG files instead of JPEG files? I was looking for such a configuration option (in Settings) but came up empty-handed.

My device isn't rooted and I'd like to avoid rooting, if possible.

NB: My question is somewhat related to this one, but I am indeed looking for a way to revert to PNG as a lossless default format, so I'd hold this is not a duplicate. I also scoured questions on the screenshots tag, but nothing useful there either.
Unfortunately I also don't know a way how to configure the format used by the system screenshot function that can be triggered via Volume-Down + Power.
However if you can trigger your screenshots via adb and the screencap command let you choose which image format is used. You can select if by the file extension:
screencap /sdcard/screenshot1.png

If you don't use a .png file extension you seem to get the raw pixel data with a small header in front containing width, height, pixel-format and the color-space (SRGB, DISPLAY_P3 or UNKNOWN).