Actually, why not learn few more chords to the song? Nothing wrong with that. It doesn't even matter if audience will acknowledge it or not. We owe it the song and to music in general. Why not do it the best you can, and not just do it .

And we can't measure it how much audience likes it or not.. Most of them would say it's nice even if you do it 10X worse. So, do the best you can. It feels really good once you get it right.