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.
I keep a reference to some simple but painful task if you forget a common or something. I am new to Yii and this took awhile for me to figure out. Everything I read said do this or do that and not a single one worked for me. However, the following did.
To extend the functionality of you web application relative to your requirements you are supposed to use existing yii core libraries or use external libraries. There are some steps to ensure security, uniqueness, modularity, performance and to avoid rework in future.
Sometimes the active form we wish to use to edit/add a new element on our database is too small and we believe that is much better to use an AJAX'ed dialog/slide form rather than reloading the page to just display one or two fields.