Hi guys.
I will try to post something as an example. It might not be in English.
I am not saying choral mode is wrong, but if you want more acurate harmonies and more musical harmonies SCALE mode is the way . Although probably with some simple songs it would work almost the same as in choral mode.

And Mr . Gary is right.If you can't control your voice and sing in the right key, harmony processor is probably not for you.It doubles and triples every mistake you do ..
I am not a singer. I sing only because I have to, but I am pretty acurate with singing . Although my voice is nothing to brag about.
But, I did sing harmonies a lot before.
That is why I am always critical about harmonies..