Here an example where the four glyphs mentioned above can get special treatment.
Be it that no tracking is applied or different tracking values.
I just added four GREP Styles to the already existing ones.
The used character style "Reformat" just applies a yellow fill.
[\x{0020}-\x{00FF}](?=[\x{FF09}])
[\x{FF08}](?=[\x{0020}-\x{00FF}])
[\x{3001}](?=[\x{0020}-\x{00FF}])
[\x{3002}](?=[\x{0020}-\x{00FF}])
You could use four different character styles for the four added GREP Styles of course…
The closing bracket ） \x{FF09} is a special case.
Also: we could add some more styles. Eg. if the right space of a glyph like 。 \x{3002} followed by an English character is too wide. There are always things to refine…
Also note: Here in my example the English "?" has mixed formatting. The color is overridden from red to yellow, but the underline is not. So the yellow color is from the GREP Style [\x{0020}-\x{00FF}](?=[\x{FF09}]) and the underline is from the first GREP Style: [\x{0020}-\x{00FF}] .
Uwe