In the case an individual has an ongoing relationship with a company where data is collected and processed frequently one can make repeated Subject Access Requests (SAR) for free as long as they are not "manifestly unfounded or excessive, or if an individual requests further copies of their data".
I interpret this to mean I could make repeated request of the company as long as each request is for unique data (eg. "data for the last X time period") and the frequency X is not manifestly excessive. This could be termed a retrospective SAR.
Could one, instead of sending a new SAR every X time period make a prospective SAR, eg. "You can fit a smart meter, but I want you to send me all the data it transmits every X time period"?