In some circumstances, we cannot use the Inputbox's comment or commenttitle features to create a new section on a page.
To reproduce:

• Either in a fresh Private Window,
• Or, as a logged-in user with your editing mode preference set to Always give me the visual editor if possible
  • click either button at https://www.mediawiki.org/w/index.php?title=User:Quiddity_(WMF)/sandbox&oldid=2877021

Expected:

• It ''should'' open a new-comment box that is prefilled with the content of User:Quiddity_(WMF)/sandbox2/en. This works with a logged-in account with an editing-mode preference of Show me both editor tabs, or in a Private window that has previously selected a wikitext preference)

Actual:

• that doesn't work for anons, because the visualeditor-welcomedialogue interferes on the first load.

Note: I looked at the Inputbox docs, and saw the mention of the useve parameter, but it only describes how to force VE to be true. I tried experimenting with adding useve=false to my sandbox, but that had the opposite result and merely forced a logged-in window to use VE. I'm guessing the code simply looks for any value assigned to the parameter and interprets them all as 'true'?