“It’s for you, judge”

What is the objection to a solicitor using their own efficient telephone conferencing system instead of an approved telecommunications provider for a telephone hearing under the CPR?

CPR PD 23A para 6.10(1) says that the provider must be approved although the court might be persuaded for good reason to allow the requirement to be departed from. Perhaps the hearing will be short and uncontroversial or the solicitor organising the hearing has an in-house telephone conference system which is efficient. One of the principal reasons for the requirement is that the provider will record the hearing whereas the judge may be conducting it in accommodation in which recording facilities are not available.