Westergaard (2021) presents an updated account of the Linguistic Proximity Model and the micro-cue approach to the parser as an acquisition device. The property-by-property view of transfer inherent in this approach contrasts with other influential models that assume that third language (L3) acquisition involves the creation of a full copy of only one previously existing language in the mind. In this commentary, I review Westergaard's proposal that first language (L1), second language (L2), and L3 acquisition proceed on the basis of incremental, conservative learning and her view of the parser as the engine of the acquisition process. I then provide several arguments in support of her position that crosslinguistic influence in Ln acquisition may flow from any previously acquired language. [For "Microvariation in Multilingual Situations: The Importance of Property-by-Property Acquisition," see EJ1300541.]