Dispatch firms are not currently required to record destinations or fares charged, SB... hence the information available from most traditional dispatch firms would be of limited use to Revenue in conducting driver audits. Conversely, drivers who work for app based firms such as Free Now can get an annual statement showing all income from cash and account jobs dispatched by the firm... obviously Revenue will know that and expect to see the same in the event of an audit.
In any event, none of that has any relevance in facilitating contact tracking. Restricting all taxis to private hire may make sense in that regard and could require amended regulations requiring dispatch firms to record the purpose of the journey and the destination. Such enhancements may indirectly assist Revenue in enforcement of compliance depending on definitions specified.