This Space Engineers plugin allows mod developers to attach Visual Studio and other IDEs to the game and use breakpoints. As a side effect, this will disable Keen's additions like mod profiling. This plugin will only work on local mods. Additionally, this plugin unloads the modded models when the game unloads. You should no longer have to restart the game to update a model.
In order to use this plugin, you should install Plugin Loader. After installing Plugin Loader, simply find and enable Mod Debugging in the plugin list from the game menu.