It adds steps rather than obstacles. A York County company files, closes, and gets taxed under South Carolina rules, and South Carolina law will govern the purchase agreement and the seller's non-compete.
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The practical differences show up in three places. Entity records and any transfer filings run through the South Carolina Secretary of State, and buyers typically condition closing on state tax clearance, which has its own timeline that should be started early. Permits, including air and wastewater, are issued by South Carolina DHEC rather than North Carolina DEQ, so the environmental diligence is reviewed under South Carolina rules. And restrictive covenants are read under South Carolina law, which differs from North Carolina's in how courts treat overbroad terms, so the non-compete has to be drafted for the right state from the start rather than adapted from a North Carolina template.