It occurs to me that current conditional markets may be skewed in favor of Kamala Harris due to her being the automatic replacement if Biden suddenly dies or needs to unexpectedly step down, and her being the natural compromise candidate in any sort of hard-fought contest.

Here's a conditional market purely asking who the replacement will be in the event of an "orderly handoff."

The market is cancelled (Resolves "N/A") if there is NOT any such "orderly handoff" from Biden to an alternate nominee. A competitive contest at the convention is fine, as long as Biden has amicably passed on the nomination himself. (e.g. isn't putting his own name forward during the convention, hasn't been muscled out only to put his weight behind a loyalist during the convention itself. I don't know how convention mechanics work, let me know if any further clarifications are needed.)