Ideally Wavelab would decode LAME
Lame does not included a decoder. But it is sometimes associated with one called mpg123.
Don’t forget that Fraunhofer created the mp3 format. On another hand, lame is not a well maintained project. For example, last version I tried 3.1 did not build successfully on Mac.
Putting some effort to support some non-official version which is not well maintained either, is difficult.
Now, I know this Lame version is popular, because of historical reasons (availability), therefore I don’t discard your POV.