Etcher, (which runs on windows, mac, and Linux), literally makes it that easy. Oh, there is a gear/setup icon. In setup, Etcher gives the option to keep the ISO partition at full size. This can be helpful when creating live boots when the ISO partition is smaller than the USB.
Rufus, the interface exposes all the settings; Not that the process is different. 1) Select the device/usb, 2) Select the ISO/boot selection ... a slider is provided for persistent storage, of the ISO partition ... 3) start.
In my case, the windows operating system wants to plug and play the USB, and The step of permitting the program to modify the device ... When The system asks for permission; but asks when Etcher wants to make changes. The wait times make it confusing to see if Etcher is working.
So in my case, Rufus works better for windows. Yes, there is a difference between an installed copy and running a portable copy. I'm using the portable copy option.