the OEMs who used the Snapdragon X1 Elite in windows laptops, from https://en.wikipedia.org/wiki/List_of_devices_using_Qualcomm... :

Acer, Asus, Dell, HP, Lenovo, Microsoft, Samsung

Looking at the SOCs used, only Dell, Microsoft, and Samsung used the 2nd fastest SoC, the X1E-80-100 - the Dell and Microsoft laptops could be configured with 64GB soldered.

Samsung also used the fastest SoC (the only OEM to do so), the X1E-84-100. From a search of their USA website, you're stuck with only 16GB on any of their Snapdragon laptops. :(

I'd hope whichever OEM(s) uses the Snapdragon X2 Elite Extreme SoC (X2E-96-100) allows users to configure RAM up to 64GB or 128GB.