Found this way of placement, rigidly binding, based on the user's screen resolution, bottom of picture:
https://cdn.discordapp.com/attachments/550321613586038804/727142099480215602/2020-06-29_151814.png
But still need to look for options.
get it out of the scroll Gui
About gui scroll... There are several location options for gui: top, left, center, goal, screen. https://lua-api.factorio.com/latest/LuaGui.html
For Fi main gui I used "left" location, like many other mods. And when a lot of elements accumulate on the left, a scroll may appear.
You can analyze which element goes out of bounds with Ctrl+F5 and Ctrl+F6 keyboard shortcuts.