https://i.imgur.com/deadIeH.png
When typing in the twig editor the syntax highlighting gets messed up without fail, the only way to get it somewhat accurate again is to close and reload the document.
Also, it should be possible to keep the split view "disabled", or that it keeps it dragged all the way to the right. There hasn't been a single instance for me where the html/php code generated has any value for me because of missing variables (or the "unexpected token 'form_theme' in C:....." errors).