I think they just worked around him–it was suggested that he was in the castle, but working on something. The important things were happening between Snow, Johanna, and Eva anyway; Leopold just wasn’t a relevant factor. Fair enough to assume that he (the character) was indeed present based on the fact that he was at least mentioned, just not on screen.
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Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing