I use a lot of different sidebar Icons. So many in fact, that I have to scroll a super long time to access the ones I need. I have two features to suggest which could drastically increase user convenience when you use a lot of Icons. I'll provide example images for what I mean but they probably won't be perfect 😅
Suggestion 1: Sidebar Icon Folders.
If you have used Discord before and are in a lot of servers, you are probably aware that it comes in handy to make folders to sort your servers. Here is an example Image. The same thing would be useful for Sidebar icons as well. Additionally, folders for icons would mesh well with the ability to change the order of icons.
Suggestion 2: Additional Sidebar Rows.
Another solution to having so many icons that you have to scroll down to see them all would be a setting to change the amount of sidebar rows. Here is a concept Image i made in google slides. Of course, an extra row of icons would definitely take up more space. A way to reduce the amount of space it takes up would be to also introduce the ability to change the size of icons. Making them smaller would both decrease the amount of necessary rows by making more icons fit in a single row as well as making each row thinner because the icons are smaller.
Conclusion
By adding these suggestions together, the sidebar could reach a far greater level of optimization and efficiency. And with Opera GX being a browser intended for gamers, I believe that would be greatly appreciated.