IzioDev posted the Toccata pre-activation pre-release, v1.3.0-toc.5, describing it as a real-mainnet sanity test for different node histories, pruning states, upgrade paths, and operator setups. The pre-release did not activate Toccata on mainnet. (source) (release)
The same announcement also turned the fee-policy transition into an integrator checklist. RPC-submitted transactions were already checked against the upcoming minimum standard fee policy, while zero-fee transactions remained consensus-valid; wallets, SDKs, and transaction-submitting software were told to verify their fee logic before the final release. (source)
The release had an operational warning as well: the database upgrade was one-way, so going back to an earlier version would require resyncing. Larger operators were told to test with a limited subset of infrastructure or hashrate rather than move full operations at once. (source)
All sources link to public messages in the Kaspa Core R&D (public) Telegram channel.