Great. I never thought about 3 button mode...
at a first glance:
- You are calling freeMemory() instead of tree.freeRam()
- "confirm to RUN" is the default associated label in order to let the user be warned about starting action. It will be possible to toggle it on/off by next setBehaviour method in the next version
- about the label missing ... It should'nt. I'll try to investigate better
EDIT in the quick tour doc there was the wrong reference to freeMemory. Is has been incorporated by menwiz class and changed to freeRam, as it returns the free ram and not the prog or eeprom memory. Please be sure to use the latest version of lib at GitHub - brunialti/MENWIZ: ARDUINO LCD menu library: short user code to manage complex menu structures