There is a lot of stigma and even classism regarding piano playing.
"You have to learn to play with these standard big keys, because this is simply the standard."
A standard that already elimitates 87% of women to play an octave comfortably.

"But when you are used to your adjusted smaller keys and then you have to play at an concert, there won't be a grand piano with these smaller keys specially for you"
Make it available then?
If you have 3 standard sizes "small, medium, large", and that becomes the standard. It will not be an issue right?
Look at bass guitars for example. They have short, normal and large scale models.
Why can't it be done for pianos as well?

Many research has been done by this amazing team of PASK and there is clear evidence that there is a need and a market for smaller sized pianos.

So please make it happen! It would mean the world to so many enthousiastic piano players who struggle.

Piano companies say it's not viable and cost-effective, but I would pay top dollar to get something that would fit my hands. Instead, my money will now go to Narrow Keys :)

I'd prefer smaller keys on a digital piano, which would also seem more easily accommodated by manufacturers.

Schools, universities, and community colleges would also make good marketing targets, to introduce the idea (appeal to innovators and students of all ages) & students would also later buy their own.

Don't forget those older students - sometimes they have more assets to spend on things like this, plus with an eye to leave to their heirs, or buy for their kids? grandkids.