I’m not sure what would be symlinked to what here? I could symlink .stignore to .stglobalignore instead of using #include, but I’m not sure how that relates to the issue of “each time I set up a new PC, I need to remember to go and twiddle some extra settings somewhere else to enable my standard ignore list”
And don’t have any other things in the ignore file as this is the only thing you need to remember to type in?
That is correct - I’ve not yet found a use-case for local ignores, but pretty much all of my folders have global ignores in them (Code folder ignores .cache, Downloads folder ignores *.partial, Photos folder ignores Thumbs.db and .DS_Store, etc)
#include’ing a synced file is the best way I’ve found of making that happen - The only pain-point with this approach is that I consistently forget to enable it 
(With the consequence that junk which is supposed to be ignored gets into my metadata index - so I go back and add the ignores, delete the files… and then the ghosts of these files haunt me because of file names lingering forever - #5 by shish and my repos are marked as “out of sync” until I nuke the whole setup and configure from scratch with a new folder ID)