> ‘ȝ’ was used to write two completely different sounds in Middle English
Was it, though? By comparing English and Dutch you can clearly see that one of the ways this harsh "gh" changed in English is it became "y" as in "yesterday". "Weg" (Dutch) - "way" (English), "gister[en]" (Dutch) - "yester[day] (English), etc. I wonder if at the time pronouncing it as "gh" was still common and this would make using the same letter in some words much more logical.
Was it, though? By comparing English and Dutch you can clearly see that one of the ways this harsh "gh" changed in English is it became "y" as in "yesterday". "Weg" (Dutch) - "way" (English), "gister[en]" (Dutch) - "yester[day] (English), etc. I wonder if at the time pronouncing it as "gh" was still common and this would make using the same letter in some words much more logical.