May be I am blind, but I do not see any special characters. I suggest adding a method of quickly selecting a latin symbol, for example, to a note/experiment/etc.
The insertion of special characters is possible using the menu Edit > Special Characters. This opens the system-wide panel for insertion of special characters and symbols. If there are symbols you use often, you can mark them as favorites, making it easier to get back to them quickly. I plan to introduce in a future version an even easier way to insert special characters using the editor toolbar. At the moment, I cannot promise when this will happen but I have added your message in the list of feature request, so I will let you know when it is implemented. Many thanks for your feedback! — Charles