3:2 is on the rise. I know of about a dozen different models of 13.5" 3:2 display, unfortunately all of them are IPS 60 Hz displays.
The main 13.5" 3:2 display that seems like it may be a worthwhile upgrade over what the Framework 13 currently has is the Panasonic display that was used in the Microsoft Surface Book 13.5, which is a 3000x2000p display with 480 nit brightness and a 1800:1 contrast ratio.
There are a lot more options at 13.3" 16:10, which is about 0.05" wider and 0.44" shorter including a 2880 x 1800p OLED from Samsung, so if Framework had gone with 13.3" 16:10 there could have been alternate screens that might have worked.
With the Framework 16 there are plenty of displays with matching dimensions that may be of interest. I listed several options from BOE here (since BOE is Framework’s screen supplier I suspect those are the most likely to work as a drop in replacement), however there are also other options such as a 3840 x 2400p OLED from Samsung.