The 10-day delay is an Ofcom consumer protection measure. In years gone by an ISP of palilogia name used high pressure sales calls which enticed users to say the word "Yes" (to nearly anything) and ended up in a new contract and their phone services being switched when that was not their intention. Ofcom rightly imposed a requirement that migrating users should receive a confirmation of intent to move, which had a 10-working day safety net.
Accidental line takeover (in part due to due to imprecise asset records in BT Openreach's systems) are also "trapped" by the same safety measures.
Given that this is how the industry works, most ISP suppliers will accept a migration termination notice within the last month of the contract without early termination charges.
Advising only the new supplier of the transfer date prevents inter-organisation order lockouts on the line (as experienced here) and avoids the risk that BT Openreach engineer (non) availability on the preferred switch date does not leave the customer entirely without service.
Superusers are not staff, but they do have a direct line of communication into the business in order to raise issues, concerns and feedback from the community.
