Sus triads can add a nice flavour and echo the chords here which are F#m11 and FMaj7#11. Both have a sus triad at the top.
F#, A, B, E - F, A, B, E
The backing riff is in F#m and 11/16, this might seem really weird but when I wrote it I was thinking of a normal bar with four beats then added an extra 3 half ones on the end. Soloing over it is easy as you don’t have to be as rigid in the timing, and it is desirable to play over the bar lines and stretch the phrasing.
The riff and first phrase are taken from a song called ‘Potential’ by my band Indighost.
When improvising over this at first try to lock into a 16th note groove to catch the timing, then just float over the top and see where the mood takes you!