This is a small thing, but I’d expect that the example below would replace the highlighted tokens, not add to them.
It’s more difficult when I want to add a token to the beginning of the string.
This is deliberate behaviour. There are some differences between how line edit controls work on Windows and macOS, so to try to create a consistent behaviour for the software on both platforms we actually ignore the cursor position and selection in the line edit. After you’ve selected the whole lot, hit Delete before you click the button to add the ingredient. And to add an ingredient to the start of the recipe, cut the selection to the clipboard, add the desired first ingredient, then paste the cut text in.