@oldschool
Superduper mode 'only' disables the Javascript just in time compiler. Edge has more flags related to security. I tred a few, but they broke the websites I have in my bookmarks. Edge tracking protection already monitors my engagement with websites (baed on wether it is bookmarked and my clicking behavior on that website). So they have a mechanisme to see whether I frequently visit that website (bookmarks).
Edge can apply stronger mitigaties for websites I do not visit often (not bookmarks and not in the known website list of Smartscreen) when I visit a new website how interact with a website (click behavior) and how many other people visit that website (Smartscreen statistics). So this part of Edge can be trained with an artificial intelligence system to decide whether less or more restrictions should be applied.
I have a separate shortcut for my hard-mode profile in which I also use the --inprivate start switch. Today I checked the list of blocked trackers in my hard-mode profile and it reported zero trackers blocked. It seems that Microsoft respects the privacy promise of its incognito mode (which M$ calls inprivate mode). Assuming the new feature uses the same user-engagement monitor as tracking protection, I trust this new security strict mode with --inprivate will also nullify the visited sites statistics.
I am using two profiles, because SecurityNightmares posted a thread on the benefits of using three profiles. Because I never ran into troubles with my easy mode profile, I dumped the completely default profile for banking and now am using easy-mode for banking also (disabling uBO for my bank only). The two profiles (easy and hard mode) have different settings on how I interact with my browser, site permissions, Edge build in privacy and security and different uBO modes and blocklists.