Yes, it will be very useful but I don't know which is the complexity to integrate in IDE code.
Another option is coding as an app helper with B4J and Sqlite as DB (an icon present on Windows Notification area that let you copy and paste the font Unicode to B4X code)
Similar to what @fredo mentioned for FontAwesome: for Material Icons, I found this one: https://material.io/icons/ ; at the top of the page there's a Search field where you can enter text. When you click an icon, click 'ICON FONT' at the right of the bar that comes up at the bottom of the page, and the hex code will show up.