if the input file format is the same as output don't convert file

currently curlew will convert the input file if it is the same format as output file, an example.
you have a bunch of files one of them is .opus your output is set to opus also.
it will convert the file.
would it be possable to prevent same file format conversions?
if a audio file with the same format is converted again, you get audio degradation
thanks,
Majid Hussain