Will post this on the end of the other thread too but I have just found this:
If you are identified as a contact and asked to self-isolate by NHS Test and Trace, including by the NHS COVID-19 app you may be entitled to a payment of £500 from your local authority under the Test and Trace Support Payment scheme. If you are the parent or guardian of a child who has been told to self-isolate you may also be entitled to this payment.
^Presumably that is all of the 'thought' that has gone into the situation I've been talking about. Still doesn't tell us if we would be seen as taking unauthorised leave or able to work from home or anything - need union specific advice on that.