When I first installed edge dev, I was disappointed to see that the omni bar and right-click menus had been given rounded corners. There was some feedback in one of the earlier threads suggesting that the rounded corners be made square again(https://techcommunity.microsoft.com/t5/Discussions/UI/m-p/409048#M63). Do we know what became of that feedback? Was it rejected?
I am sure that Elliot got that through to the product team. We aren't privy to the prioritizing that they use for various features. If they are going to make your suggested changes, it will be in their own time. The only announcements that we have are those in the What's Next and What's New pages at Microsoft Edge Insider.