yes the original splitter contracts and ui support exist at explorer.splits.org as to the "take their old users with them" - the unsatisfying answer is "tradeoffs". in our case, our other product (app.splits.org) is a wallet so the user base isn't 1:1 w/ the protocol.

Splits protocol explorerCreate and manage Split, Waterfall, and Swapper contracts. Battle-tested, audited smart contracts for payment flows, widely available across the EVM.explorer.splits.orgSplitsTreasury and personal accounts for onchain builders. Agent-ready banking tools, self-custodied multi-sig, and open-source contracts for payment flows.app.splits.org