A big problem I've hit with the Yii-Bootstrap extension is that all AJAX requests are initializing Bootstrap because of preload. This is a huge waste of resources, especially when using AJAX-based file uploaders that split the file into chunks. Large file uploads using that method could be initializing bootstrap hundreds of times.
Many people want to use downloaded extensions in their own way. As for me most of the extensions require me to correct Yii::import() instructions inside their source code. All these extensions are directory dependent. To avoid the situation described above, I suggest to implement pseudo-anonymous aliases: