Views, Panels, Block not translating
I thought there was already support for translatable pane titles in Panels with the i18n_panels submodule. However, looking at Issue #117934 which is currently marked fixed, there are still people providing patches. Though that issue title states it is for translatable Panel PAGE titles, the patch on comment #106 actually modifies code to make pane titles translatable. 

Note that from an architectural perspective the approach in comment #106 is frowned upon because you are not supposed to pass dynamic text through t().  I would consider this a small permissible hack to get you across the finish line without wasting too much time.