Being cavalier with proofreading =/= being cavalier with number size.

Well, I didn't want to declare a proofreading error because 3^^^3 does technically fit correctly in the context, even if you may not have meant it. ;)

I was thinking the fact that we are so cavalier makes it easier to slip between them if not paying close attention. Especially since 3^^^3 is more commonly used than 3^^^^3. I don't actually recall Eliezer going beyond pentation elsewhere.

I know if I go that high I tend to use 4^^^^4. It appeals more aesthetically and is more clearly distinct. Mind you it isn't nearly as neat as 3^^^3 given that 3^^^3 can also be written and visualized conceptually as 3 -> 3 -> 3 while 4^^^^4 is just 4 -> 4 -> 4 not 4 -> 4 -> 4 -> 4.