Samsung S4 mini (i9195 -- note no x or i suffix) is nice small phone (<110g). It also seems to be well supported by PostmarketOS.
https://wiki.postmarketos.org/wiki/Samsung_Galaxy_S4_Mini_Value_Edition_(samsung-serranove)Except that ... well.. there are apparently two or three different "S4 mini"s, and I have msm8960-based one, which is very different -- serranoltexx. I can flash lk2nd, but it will not boot when flashing @PostmarketOS.
If you have spare S4 minis, let me know, I don't have enough of them at the moment.
And this is kind of funny: typo not mine.
[131635.870585] usb 1-1.2: New USB device found, idVendor=04e8, idProduct=685d, bcdDevice= 1.00
[131635.870631] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[131635.870654] usb 1-1.2: Product: MSM8960
[131635.870672] usb 1-1.2: Manufacturer: Sasmsung