I’m not familiar with the Boss product you have but it’s all in the transferring / downloading / rendering stage.
My recording program used the term “rendering” and then has many options for what you want your audio to end up as when you take it from that DAW or program you use.
Just keep in mind that when you convert an mp3 to a WAV file you won’t get a better higher quality file, it’s just being converted by name not highe quality so don’t do it for that reason.
You can still do it of course if you need that .WAV extension for some other reason instead of an .mp3