So, when Okrand tries to give a gloss definition for {chegh}, he has to add the word “to” to the gloss. {chegh} doesn’t mean “return”. It means “return to”.
{chegh} is listed as just "return" in TKD (in both K-E and E-K sides), and also glossed as just "return" in the body of KGT. The definition "return (to)" in the KLI new words list was obviously added to distinguish it from {tatlh} "return (something)" when that word was revealed, presumably by whomever was the maintainer of the list at the time. The "(to)" is there to distinguish the meaning of "return" where the subject is going back to a previous location (which is {chegh}), vs. "return" where the subject is putting the object back to where something belongs (which is {tatlh}).