I am Sebi from the Editor X Team.
Thank you for taking the time to share your issues and suggestions for dealing with them.
We mentioned it recently on the Partners Community Roundtable for the Editor X Beta launch we brought over Corvid and Wix Data as is from the Classic Editor and we plan on rethinking how it is impl and new technologies very soon. Your points definitely help us understand what issues we have to fix on our product, so continue to share with the rest of the community and start conversations.
In regards to the bug you mentioned, we are aware of this issue. It happens when you scroll down on the page, the dataset is added very far from the viewport. If you stay scrolled to the top you should experience any issues adding datasets on your site. We hope to have a solution for this soon!
We would love to hear more from you in the future!