Of course I tried this. This can be done with almost all browsers or binary releases. As for adding yet another browser, make sure to understand what KaOS is and what it is not. See for example:
There is an understanding, selection for applications used for the same goal, will be limited to 5-6.
Any new means another browser will have to leave, and since Brave, Vivaldi and several more like this have no benefit for you as users whether you download and unpack yourself (as browsers in KCP do), or get it from the repos, those will not replace the existing options.