Potassium tert-butoxide is widely known in organic chemistry as a bulky base used to promote elimination reactions while minimizing competing nucleophilic substitution, and does not require a citation.
The claim states a foundational, textbook principle of organic chemistry: that potassium tert-butoxide acts as a sterically hindered base favoring elimination over substitution. This is a matter of common knowledge taught in introductory chemistry curricula, and none of the retrieved papers specifically target or test this textbook property as a novel empirical finding. Therefore, STEP 0 classifies this as common knowledge.