Hi there - I remember you posting but don't quite remember the history.
My take on this is he would like to be friends with benefits, and have sex when it is convenient to both of you, but not really be "friends" or "dating". If somebody wont respond to texts but messages me when they want to know when we could get together I would just consider it that they wanted casual sex. Not that they didn't like me, but that they didn't care for me and my well-being ahead of their penis.
If I realized I wanted more than that, I'd discuss it with them, if their words or behavior kept supporting they were looking for convenience but not an actual relationship (be it friends with benefits or romantic), I'd not waste my time unless that was what I wanted from the relationship too.
Happiness will never come to those who fail to appreciate what they already have.