We have just started to compile a comprehensive list of Marlin 2.0 features and their memory usage on 8Bit boards and what features you can disable safely to gain more free memory. Check out the new page (Patrons only): https://www.crosslink.io/marlin-2-0-memory-usage-by-feature/.
This is especially interesting if you have ATMega1284p based mainboards like in the Anet A8 or Ender 3, which only have 128KB of program memory.
The page will be updated frequently in the next weeks while we discover new features of Marlin 2.0.