SpecialItemByTitle takes a page title from another wiki as one of its parameters. It then uses a Title object to represent this internally - but that is dangerous and misleading. The rules for titles on the local wiki are not the same as the ones on the target wiki. A title containing a : may be in a well known namespace in one but not the other wiki, changing the canonical name utterly.
Instead, SpecialItemByTitle should use a SiteLink object to represent the title and target wiki internally. Title normalization requires an API call to the target wiki, and should thus be optional (or disabled).