Legato issues

I find Legato sort of a problem in how they implemented it. The slide is not a true slide as you can still hear the initial hit, especially if you slide down rather than up. Has this been addressed already?

You're thinking of slurs. Legato is literally just the notes being played end to end continuously without silence in between. A slur is when legato notes are all strung together without re-articulating each note.