Being devils advocate. It all depends on where the conversion takes place.

If the people processing the various sources into one contiguous file are doing some clever filtering, glitch removal etc, why throw away the effort?

If the processors have archived in MP3 then it is a waste of time.

Know where the FLAC file comes from.

If you are converting - do you really need to waste capacity? Or is it for neatness with available playback software &/or documentation apps?