Project Director Stephens disappeared from his apartment only to be replaced by a mole but later was around to receive a note in Welsh?
EDIT: Ya a key part of the original entry was omitted from the comic where the SCP-2952-2 population undo their retribution.
"Two weeks later, the mole disappeared from its containment area and was replaced with Director Stevens, and the poison ivy and mushrooms disappeared from the homes of the construction workers."
Also in the addendum Foundation personnel are able to ride on SCP-2952 by automatically shrinking to an appropriate size and enlarging back upon exit.