We are working on the speed of the frontend itself now. When we finish the work we will start the admin part (customizer). Many things need to be considered, such as tests and the inheritability of updates. All should be step by step to avoid problems and make all gentle.
XStore is not slow – https://tools.pingdom.com/#5db89288b5000000 , but we know that there are things that can be improved and it will be done.
Sometimes slow speed can be a result of your hosting service. Because even with the default WP theme site speed could be slow.
