Replacing Icons

Hi all,

firstly big props for Braz creating this awesome skin. I have tried them all and got stuck with it.
Im currently running it on Windows in order to customize it and transfer the design later to my Android based TV or Linux based NAS.
Gotta say although i use Kodi for years, i just started to actually look deeper into it.

There is this great feature to change the icons for the menu entries. This works great on the home screen. However, if you do that and click the menu item, the stock icon appears. How is that?
Second question: Are there any vector formats supported by chance for these icons?

Thanks