Primitive TypedData fields are not cast properly

Problem/Motivation

I would expect integer fields such as timestamps to be cast to an int but instead a string is returned. For example:

/** @var \Drupal\aggregator\Entity\Feed $feed */
var_dump($feed->getLastCheckedTime());

// Actual: string '1411796607 ' (length=11)
// Expected: int 1411796607

Proposed resolution

I'd like to know if this is expected or whether there it's an issue? Or maybe, a link to an existing issue?

Additional info

tim.plunkett pointed out that FieldItemBase::__get() calls getValue() rather than getCastedValue().

  /**
   * {@inheritdoc}
   */
  public function __get($name) {
    // There is either a property object or a plain value - possibly for a
    // not-defined property. If we have a plain value, directly return it.
    if (isset($this->values[$name])) {
      return $this->values[$name];
    }
    elseif (isset($this->properties[$name])) {
      return $this->properties[$name]->getValue();
    }
  }