All the nifty i18n-related helpers in Twig\Extension could be moved to Wikimedia\ToolforgeBundle\Service\Intuition. This way I can for instance use msgIfExists() in my PHP code. The Twig helpers can instead simply call the methods in Service\Intuition.
Also, I'm not sure how Wikimedia\ToolforgeBundle\Service\Intuition works, but it would seem I can't type-hint it and use the Krinkle\Intuition methods, even though it extends Krinkle\Intuition. Maybe it's not registered as a public service?
This is the one barrier keeping XTools from using ToolforgeBundle. See i18nHelper for it's implementation (basically verbatim the same as ToolforgeBundle's Twig\Extension, except in a public service).