Hi Arian, thanks for reading!
There are many ways to achieve what you want. Probably for a small predefined set of themed CSS you could load all of them (bundled, minimised, etc) and then use a selector to branch them. Eg: <body ng-class=”theme”>. That will be quicker than loading the file dynamically each time you change between themes. This will depend on css file size, complexity and number of themes.
On the other hand, the dynamic link approach is followed by angular-css so you should be fine. You probably don’t have to complicate things if you are not experiencing any issues.