Feature request from JamesAnelay, posted on GitHub Nov 12, 2015
In M1 to add a new Import file type handler e.g .tsv I need to add a new file with the class Mage_ImportExport_Model_Import_Adapter_Tsv in a local codepool (which sucks).
It looks like this is similar in m2 (https://github.com/magento/magento2/blob/develop/app/code/Magento/ImportExport/Model/Import/Adapter....)
$adapterClass = 'Magento\ImportExport\Model\Import\Source\\' . ucfirst(strtolower($type));
Would be nice to be able to add a new import type via XML so I don't have to touch the Magento namespace. As is the case with Export types.