Why would you want to do this?
Well, when learning a new song we all come across strangely named chords we do not play very often. Rather than getting stuck at that point, play a chord that you do know. I guess I have done this all my playing life and managed very well. I do understand how chords are created and knowing which chords can be simplified and to what, has always been no problem for me.
I did in fact always set out to learn the more complex chord (and thought that perhaps I was cheating in the short term) but hey - so what?
As an example, I recently learnt what most people consider a difficult song, namely "I'll See You In My Dreams". Two chords which gave me problems were D#maj7 and Amaj7. So whilst learning the song, rather than let the chords stop me progressing I played D#7 and A7; much simpler and easier and no hassle!
I have since learnt to play the chords. And I do need to get a better and more polished recording of that song on the internet, for sharing around.
I have recently seen a blog post which discusses doing this very simplification technique. And in fact suggests that on a 4-string instrument such as the uke, the more complex chords may sound a little "out of focus". I have certainly never found an issue. It is better to be able to select the chord quickly in time with the music in my opinion.
Anyway this backs up something I have always done intuitively, so I was pleased to read it in black and white - well pixels anyway.