> Typing slash ( / ), for any reason apparently, and in any context, pops up the Basic Blocks selection window. If you type, for example, "10 / 2 = 5", or perhaps "a/b testing", or any other very common valid use of the slash symbol, you are left with that stupid popup on the screen. You have to hit ESC to close it. Pity the fool who has a touchbar Mac. And if for some reason you wanted to end your line with a slash, and you hit return after typing that /, the popup eats the slash and puts you in a new block below.

You can just keep typing and the menu will close. The vast majority of the time, it doesn't actually interrupt the flow of typing in content. This happens even if what you are typing matches with a menu item. As you said, you have to press enter to actually invoke one of the actions in the menu.

Using a single key to invoke a menu and then having successive keystrokes search through that menu as well as enter the text in the editor at the same time is a UI choice I actually vastly prefer over having say dedicated keyboard shortcuts for each of those menu items, or having to click a button to open the menu. It's similar to having leader-key-driven menu selection in Vim or Spacemacs (but of course different in that the editor is modal). It is a menu discoverability and ease-of-use tradeoff they have to make.