I'm enjoying this new version of Edge very much so far and I'm curious and excited about where you guys will take it. I see a TON of potential in many different areas.
Here are some ideas that I'd bring up in a meeting if I were working on Chromium-Edge:
Never underestimate the power of looks. This browser needs to stand out visually. It needs a gorgeous white-mode and a no-nonsense but slick-looking dark-mode. People like things that look good. Things that are objectively beautiful cannot be ignored or denied by anyone. It needs to be so good that even Apple-fans can't talk trash about it. It needs to look so good that people don't even want to download Chrome. Edge needs to be the best-looking browser on the market. Put your best designers on top of it and get eccentric, talented creatives from the Internet involved to throw some wild ideas on the table for inspiration. Get photographers and painters involved who know about composition and balance.
Don't necessarily be subtle about the design. Windows XP looks insane with the super bright blue and green, but I recognize it instantly when I see it even in a tiny image. I'm not saying to go that far, but don't be afraid to look different, in the best way possible. All browsers are boring. Edge doesn't have to be. You have a blank slate. This is your chance to do be unique here. I want this thing to look and feel like the interior of an Alfa Romeo; something that instantly puts a smile on my face.
Make it abundantly clear in layman's-terms that this browser does everything Chrome does (and more) because it shares the same engine. The first thing that almost everyone does without even thinking about it is installing Google Chrome when they get a new machine. People need to know they don't have to download Google Chrome to get the Google Chrome-experience. Give users a very good "why" on this one, because this is a very ingrained habit for many at this point.
Add smart UI elements to Edge. I really liked the ability to set aside tabs in OG Edge. That should make a comeback with session-management/Windows 10 timeline-integration added to it. Reading mode was also good.
Take cues from Opera, they do good stuff that's different than anyone else, and you can turn every single feature on and off, which I also quite like.
Side-bars are underrated. Everyone has a wide-screen monitor today. The content of most websites rarely fills more than 70% width of the screen. Use that space in a smart way. Maybe allow a slim version of another tab side-by-side there that shows a mobile version of a website. I would use that when I'm working on a blog post to do research.
Speaking of which, there's no browser out there that does anything unique with ultra-widescreen monitors. Here's a chance to be the first and give everyone with a monitor like that a good reason to use Edge.
Make fill form-data recoverable on accidentally closed tabs.
Open Autofill up with an API to third-party password-managers like LastPass and 1Password. Extensions for these services work fine most of the time, but they just don't work and look as good as native-autofill. Plus, native autofill pops up after I fill something with one of these plug-ins. Makes for a clunky user-experience and every browser gets this wrong.
Or even better, acquire LastPass and integrate the entire feature-set into Edge, running in the Microsoft-cloud. It would instantly set this browser apart in a major way. In this time of cyber-crime and hacking (which only gets worse with time), this is a golden opportunity. It would instantly position Edge into "safe browser"-category.
Bookmarks-management is an important part of every browser, and none of them have a great UI/UX-experience. Look at https://start.me/ for ideas. I have used them for years to create a full-screen bookmark page, sorted by categories in different boxes, with handy widgets added. It's my default homepage and it works great.
By the way, allow me to set a custom new tab page, please.
You guys really need to realize how happy many people (including me) are with dark-mode in Windows. This extension switches the entire internet on dark-mode, and it works great: https://darkreader.org/ Could be a very cool native feature.
Put strict control on extensions. The Google Chrome extension-store has several questionable and even malicious apps in there, free to download. One of the most popular pop-up blockers in the Chrome extension-store turned out to collect personal info a while back. The Microsoft Edge extension-store should be strictly vetted to keep that kind of stuff out. My grandmother should be able to install anything to her heart's content without having to worry about installing a bad extension. This goes back again on the security-positioning that I suggested earlier.
Build-in a native ad-blocker and popup-blocker. Look at the Brave Browser on how to do this right. They even make it look cool with statistics on every new tab page.
A native anti-malware filter akin to what the pro version of Malwarebytes does would be great.