I am not really into the Trap genre however there are certain artists like Bryson Tiller who have some soulful progressions in the music. I played over the Bryson Tiller track “Don’t” with my own synth type chords. It is rather a simple progression, just three chords looping over as below.
Emin7th, Gb7 and Bmin. See below for the video. Self explanatory.
I will be expanding my set of chords for the Trap genre as they can fit in, as long as the melodies fit in the key. The only thing that tends to offset this in this genre are the diving sub-bass lines. It seems to confuse the key if used incorrectly.