I just realized this cool feature.
- Inking and drawings done on a PDF file in the new (Chromium based) Edge can be erased in the legacy Edge, and vice versa.
- Highlighted texts in either of the browsers can also be modified And removed in the other browser.
- lastly, added sticky notes in Edge classic on a PDF file can also be seen on the new Edge.
More info:
https://techcommunity.microsoft.com/t5/discussions/new-feature-pdf-inking-improvements-more-colors-a...