It's a decent suggestion. Using multiple windows in a tile stack would be the way I'd do it, but it sounds like that probably won't be a valid suggestion. I don't think it's a such a great feature that I'd comply with DRM based web page tracking and ads for. For clarity, any site with Google's DRM will need to be seen with Chrome or you won't be able to use the site, period. You will be 100% tracked and served ads. They will know exactly who you are on any site. They will clutter your pages, tab stacked or otherwise. I don't believe Google when they say this for your safety and will stop ads. It will give them exclusive power to push ads and companies will pay them a premium to force ads in your pages. This isn't Google's engineers who are pushing this. It's Google corporate making it's engineers break the web for profit and ad dominance.
Losing the ability to block ads completely or have tab stacking - I know which way I'd go. But hey, you can't force people to do anything, and unlike Google I wouldn't, so I'll just leave it there.
Nice! This is handy. Good job.