SUMMARY
I have a display at 150% scale and several displays with no scaling. When taking a screenshot, screenshots from the scaled display look crisp, but screenshots on unscaled displays are blurry. This can even be observed when activating the rectangle select, where unscaled displays become a little blurry while the effect is active.

This issue does not occur when taking a single-window screenshot or single-display screenshot, only with rectangle-select or a screenshot of all displays. 

I will attach a screenshot of the same text taken on the scaled display (crisp), and then taken on the unscaled display (blurry). Then, finally, I will attached a cropped single-window screenshot from the unscaled display (crisp, like the scaled display).

STEPS TO REPRODUCE
1. Activate a Rectangle Select / Full-Display screenshot
2. Zoom in a little
3. Observe blur that does not occur with a screenshot of or on the same display, taken as either a screenshot of the whole current display, or of the active window on the same display that produces a blurry screenshot
4. Take a screenshot of any kind on the scaled display
5. Scaled display looks like screenshots do on previous Spectacle versions prior to Plasma 6

OBSERVED RESULT
Screenshots on non-scaled displays are blurry only if Rectangle Select / Full Display screenshots are taken. Single-display or single-window screenshots look fine across all displays.


EXPECTED RESULT
Screenshots on non-scaled displays should look crisp across all displays.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Linux Zen 6.7.8 (Arch Linux)
KDE Plasma Version: 6.0.1
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2

ADDITIONAL INFORMATION
The filesize appears to be notably larger for screenshots on non-scaled displays, even if the contents are identical. Maybe this is a result of the blur.