Being on the DAOS list and holding a Design Authority or Design Custodian appointment are two different, but related, things. The DA holds and maintains the Master Drawings. A DC can be contracted to do much of the day to day work (maintaining the Build Standard), but has a directed sub-contract to the holder and maintainer of the Drawing Set (who often wants to retain control for commercial reasons, but is not interested in the work). The DA/DC need not hold the repair/maintenance contracts.
A company may hold DAOS "approval", but if the MoD Technical Agency (the named person in the contract responsible for the Build Standard, which is what we're talking about here) deems them unsuitable, or decides their performance has deteriorated, he can (indeed, is obliged to) suspend their appointment. A suspension does not affect the company's DAOS status, largely because the DAOS section in MoD is interested in company processes and jumping through hoops, whereas a TA is interested in whether the company can do the job properly. This authority vested in the TA is frowned upon at a certain level in MoD, because by definition the posts are filled by the two lowest technical grades in DE&S; and only then if they have the requisite competence and experience, which must include, as a minimum, hands-on engineering repair and maintenance of the equipment and/or aircraft, QC, Design, and other related disciplines. Observers of current MoD practice will note these are infinitely more demanding posts than the more senior positions in the MAA, which is perhaps why so few civilian engineers would wish to be promoted into the MAA, and then forced to dumb down!
The key postholder at the DA/DC is the PDS Officer (PDSO). The company nominates him to the TA during contract negotiations. His is a personal appointment of the TA. He is, uniquely, granted financial delegation to commit MoD funding. This, because he must have the wherewithal to immediately launch, for example, fault investigations when the immediately safety of the aircraft or equipment is at risk.
My guess is no Glider DA/DC or MoD Glider Team staff have applied these mandated regs in 20 years!