Hi theomoll
welcome to the Apple (user-to-user( Community!
Apologies for the long delay in replying. Am no expert in this area, yet your post deserves some response.
Re: "I can’t disable reduce motion in accessibility settings. The toggle shows it as ”off” but the crossfades still happen. No difference between on or off."
Wondering if you have checked through Apple Support's article :
Stop or reduce onscreen motion on iPhone - Apple Support
Seems there are more than the one toggle in use ...
I guess the toggles would need to all be the reverse of what is given tin the article, in order to stop all effects:
Eg: where it says turn on, turn off
where it says turn off, turn on
You likely know much more about these settings than I do, so please excuse, if nothing here can help.
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If more help is needed with this accessibility feature, you may want to reach out to Apple Support's Accessibility Team: See: How to contact Apple for accessibility support - Apple Support
or
To provide feedback about an accessibility feature on an Apple product,you can email the Accessibility team: accessibility@apple.com.
All the best :-)