Adaptive GTK dialogs (filechooser/appchooser/etc...)

Ever since the phosh developers adopted the change with xdg-portal-gtk as the default portal, I've been having trouble using the portal dialogs on mobile. That is, I literally cannot select a file via gtkfilechooser without all parts of my body and even my phone in pain because the minimal window width of this dialog is really W I D E for mobile screen, no matter what usable scale value is selected.

An example of filechooser

I've seen recommended gtk+3/gtk4 patches from Purism that improve the usability of gtk on mobile devices. Maybe someone would be interested in applying these and these patches to postmarketOS? At least part of them, the main problem is the filechooser dialog, which is used more often than printunixdialog, at least for me.

Also, in case applying such patches is prohibited and may cause additional problems on tablets/laptops, I would like to see a custom filechooser dialog exclusively for mobile devices, at least as a portal. I can try to develop it later, I don't have time for it now.

Will someone be able to solve this problem?