Finding a touchscreen for this machine is still going to be pretty hard, but it just got significantly easier: FW released pinouts for their display connector:
Display Interface
IPEX 20879-040E connector used to interface to an eDP display. Note that there are signals defined for both USB 2.0 and I2C touchscreens. There is a PWM interface to control backlight brightness, but the display currently used on the Framework Laptop converts that to a DC LED control.
Pin Signal Description 1 BL_POWER 12-17V backlight power 2 BL_POWER 3 BL_POWER 4 NC 5 GND 6 AUXP 7 AUXN 8 GND 9 EDP_TXP_0 10 EDP_TXN_0 11 GND 12 EDP_TXP_1 13 EDP_TXN_1 14 GND 15 EDP_TXP_2 16 EDP_TXN_3 17 GND 18 EDP_TXP_3 19 EDP_TXN_4 20 GND 21 EDP_HPD hotplug 22 BLK_PWM_LCD Backlight PWM 23 BLK_OFF_N Backlight Enable 24 NC 25 NC 26 3V_EDP 3VS 27 3V_EDP 28 3V_EDP 29 3V_TS 3VS for touchscreen 30 3V_TS 31 USB_DP USB 32 USB_DN 33 TS_EN 34 TS_RST 35 TS_INT_N 36 TS_SDA 37 TS_SCL 38 NC 39 GND 40 GND