You might be able to reduce the amount of information sent to the LLM by 100 fold if you use a stacking context. Here is an example of one made available on Github (not mine). [0] Moreover, you will be able to parse the DOM or have strategies that parse the DOM. For example, if you are only concerned with video, find all the videos and only send that information. Perhaps parsing a page once finding the structure and caching that so the next time only the required data is used. (I see you are storing tool sequence but I didn't find an example of storing a DOM structure so that requests to subsequent pages are optimized.)
If someone visits my website that I control using your Chrome Extension, I will 100% be able to find a way to drain all their accounts probably in the background without them even knowing. Here are some ideas about how to mitigate that.
The problem with Playwright is that it requires Chrome DevTools Protocol (CDP) which opens massive security problems for a browser that people use for their banking and managing anything that involves credit cards are sensitive accounts. At one point, I took the injected folder out of Playwright and injected it into a Chrome Extension because I thought I needed its tools, however, I quickly abandoned it as it was easy to create workflows from scratch. You get a lot of stuff immediately by using Playwright but likely you will find it will be much lighter and safer to just implement that functionality by yourself.
The only benefit of CDP for normal use is allowing automation of any action in the Chrome Extension that requires trusted events, e.g. play sound, go fullscreen, banking websites what require trusted event to transfer money. I'm my opinion, people just want a large part of the workflow automated and don't mind being prompted to click a button when trusted events are required. Since it doesn't matter what button is clicked you can inject a big button that says continue or what is required after prompting the user. Trusted events are there for a reason.
[0] https://github.com/andreadev-it/stacking-contexts-inspector