I had a listen to these Busoni Sonatinas. To me they are a study of relating two dissimilar things together (the 4 moreso than the 5) I think you do a faithful job of interpreting them, I didn't get a sense that they needed more pedal or less, the notes modulating seem to be the "what works in this piece is..." to them. I've never gotten deep into Busoni, but the frequent modulating is something I like, recalling Cesar Franck. Come to think of it, Franck may have been Busoni's predecessor in some sense them both having lived in the same century.
Thanks Riley. An interesting comparison... Franck the blissful, devout and conservative organist, and Busoni the restless, dark and modernist piano lion. I see not much common ground in them. Their lives don't really overlap.