The Gantry development team has been hard at work on Gantry 5.3 which will include a major update to the framework including a new inheritance system.
One of the most-requested features for the Gantry Framework across platforms has been for a more comprehensive inheritance system. Our team has been hard at work developing what we believe is the best solution for inheritance, and that work is nearly complete.
Whether your site is running on a Gantry 4 or Gantry 5 framework, you should have no issues making the upgrade to Joomla 3.5. This comes after extensive testing by our development team since the initial Joomla 3.5 beta was released in 2015.