just moving them to a dedicated window.

That's the key, it's like having a separate window, but without the separate window.

At work I'll open anywhere between 40 and 100 tabs at a time, but I want to keep them near my existing tabs and not in another window. I have an extension that opens them all in a new tab group. I typically work from the left edge of the group and close out of tabs as I get through them. I can still hop between my non grouped and grouped tabs without having to change windows. And if I want to pause it for a bit then I "minimize" the group like a window.