What changes to make if an extension changed from Chrome to Edge after all the developement part is done?

have a look at the browser migration tool:

it will require some manually postediting / testing. Also we would recommend to validate in a mini test before (allways take bakckups before any conversion).

In general the tool has a potential to reduce manual work efforts

In some scenarios we coupled it also with mass replacements on plain XAML base e.g. done with notepad++