So, the first startup dialog has a check box saying "Do show again". 1. It should not be checked by default; it is a first startup dialog. 2. I say it should not even exist. UI mode is in the View menu, Appearance is in Tools > Options, that's enough. 3. The wording is not right. You probably mean "Show this dialog on next startup" or "Show this dialog on the next LibreOffice startup".
Sounds valid. Eyal, could you add a screenshot with a date to document status quo?