I think we just need tiny sinks in stalls, or rather, all public stalls should be designed as semi-ambulant stalls.
Growing up as a crutches user (hip deformity) I didn't fully comprehend that the standard stalls don't have sinks in them. I kind of knew they didn't all have sinks, but I didn't think too hard about it, I sort of assumed the reason most people flushed then came to the main public sink was to use the mirror or dryer.
I got to used to filling my personal bidet at the sink, using it, and washing it at the sink, all behind the privacy of a closed bathroom door.
When I had my hip surgery and no longer needed semi ambulant stalls, or disability access stalls, and it was just so inconvenient to fill and rinse a bidet bottle in a regular public bathroom I stopped using it.
Then a few months later started using the semi ambulant stalls again so I can use my bidet, because it turns out my lichen sclerosis doesn't like public toilet paper and I was getting really bad infections.
But yeah, personal bidet bottles are great, but they require a tap near the toilet.
Some public sinks are easy to fill a bidet bottle, but a lot aren't, you physically can't fit a bottle under the taps and because bidet bottles aren't common it can feel embarrassing to fill it at the public sinks. Disability stalls almost always have a proper tap and sink for washing toilet aid devices.