Gabe here from Shopify.
In the theme editor, you also have the option of choosing the "Picker Type" as a "button" instead of a drop-down.
The big advantage here is that the variant option then becomes instantly visible to the visitor who doesn't have to click a drop-down. This can reduce mistakes such as choosing the wrong option, and so reduce returns.
Is that what you asked, and do you think this would work for you?
See an example here how to do that:
A code change to effect wider drop-down buttons could be possible but we wouldn't recommend it because this code change could be complex and potentially cause the button text to "wrap" depending on screen-size e. g. make it look strange or distorted on mobile or tablets for example.
Hope that helps!