@halvor-raknes Opera has few/some/a lot of "holes" in functionality. Why do you not want to be a little lazy using pinned tab with opened Qwant page? I use Startpage systematically this way, selecting DuckDuckGo as default.
By the way. If Opera Team wanted to open sidebar to "whatever pages you want" like Vivaldi did, your and other Opera users life'd be more efficient and pleasurable.
Debian Bullseye, IceWM, 2 core CPU with 8 GB DRAM, NVIDIA GT520, driver 390.132, Opera Beta