I am more impressed with your practice. You have multiple considerations. I have however matched an a cappella singer with music I wrote for her singing. You can see that at: https://m.youtube.com/watch?v=mda7QMTv09M

I have written many books, a poem of which was used as lyrics for a song by a singer. I know how hard that process is to develop. I have tried to make songs from things I have written. There is this battle with the rhythm words and the bending of sound to fit.