Thanks very much for sharing these and shining light on this music. I share your interest in Russian music of this period, but all these are new discoveries.
The waltz is not far from the spirit of your own waltz in the improvisation section. It is a delightful little work, but it is especially the Sabaneyev preludes which draw me, and your recording does not disappoint. I love the rich harmonic progressions which Sabaneyev follows to the end producing such emotional depth. I really hope you continue pursuing and sharing this music.