I would argue that atleast for Czech Republic, the notice is not required if the processed data is crucial to providing the service the user requested.
You cite Article 89(3) of the Electronic Communications Act, where it's stated that "... nor does it apply to
the cases where such technical storage or
access activities are needed for the provision of an information society service explicitly
requested by the subscriber or user.".
This part was also modified several times, most recently at 2018 in 20/2018 s. 687