Ask HN: Do you plan “non-technical” work in sprints?

Title says it. If an engineering team has to do a lot of otherwise invisible tasks (backend, research, hiring, planning), should those be included in sprint planning and estimations?

It is easy to show progress when tasks are lots of little "shallow" things like HTML/CSS, configuration etc., but sometimes I feel it is hard to not feel guilty for working on the "hard" and "important" stuff, even if it cannot be expressed as a PR, or sometimes even foreseen at all.