Watch the 1 Notes-Per-String Forms online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
The final Add 9 arpeggio in the one note-per-string format is the 3rd inversion form. Measure one of ex 25 reveals the technical challenge on the 6th and 5th strings: two notes on adjacent strings in the same fret. The options are 3rd and 4th fingers or a double-stop played with the 4th finger. Try both and be patient as double-stop fingerings can take time to develop but are quite useful for solving these sort of issues.
Try all approaches when playing: permutations, melodic patterns, pedal tone ideas, fragments for punctuations, and raking.