No, and if a personalisation tool requires that, it is worth asking why.
Your pages stay where they are. You choose the spot where content should vary, usually one section on one page to begin with, and place a marker there. Everything above and below it is untouched, and the rest of your site carries on exactly as it did.
Nothing is written into your pages. The content you write lives in your own workspace rather than being pasted into posts, so there is no markup left behind in your database and nothing to unpick if you change your mind later.
The practical shape of it is smaller than people expect. Pick your busiest page, put one varying section under the opening, and leave the rest alone for a month. That is enough to tell you whether it is doing anything. Sites that keep going tend to end up with varying sections on three or four pages, not thirty.
What you should expect to spend real time on is not installation. It is deciding what you actually want to say to different visitors, which is writing work rather than technical work, and it is the part that decides whether any of this pays for itself.
This is one atom from the Spectare content library. Spectare assembles the right atoms for each visitor in real time, based on who they are and how they arrived.