Kurt Börner’s piano music is largely obscure, representing the transition into post-Romantic tonal idioms. The work is notable for its exploration of rich, sweeping arpeggiated figures.
The main hurdle is achieving seamless transitions between registers using fluid pedaling.
Comparable difficulty and character — good candidates for what to learn next.
Ballade is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
Ballade is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Gymnopédie No. 1 by Erik Satie, La cathédrale engloutie by Claude Debussy, Gnossienne No. 1 by Erik Satie — see the full similar-pieces list on this page.