Where this 6402.303 UCC - SALES chapter allocates a risk or a burden as between the parties “unless otherwise agreed”, the agreement may not only shift the allocation but may also divide the risk or burden.
Wis. Stat. § 402.303
Allocation or division of risks
Official source: Wisconsin State Legislature. Reproduced from public-domain Wisconsin statutes; confirm against the official source for the current text. Not legal advice.