Suggestion from Juergen:
Boot could automatically inject any TransactionExecutionListener beans in the context into a PlatformTransactionManager or ReactiveTransactionManager that it configures, along the following lines:
@Bean
public JdbcTransactionManager transactionManager(DataSource dataSource, Collection<TransactionExecutionListener transactionExecutionListeners) {
JdbcTransactionManager tm = new JdbcTransactionManager();
tm.setDataSource(dataSource);
tm.setTransactionExecutionListeners(transactionExecutionListeners);
return tm;
}