If, when you say "skip poker planning for theses tasks and adds blanket numbers", you mean that you time-box them, then you are talking about a regular practice in scrum called a Spike:
A spike is an experiment that allows developers to learn just enough about something unknown in a user story, e.g. a new technology, to be able to estimate that user story. A spike must be time-boxed. This defines the maximum time that will be spent learning and fixes the estimate for the spike.