I only just paid attention to this one…

“item (last) of list” = the last one, at position “length”
“insert … at (last) of list” = *after* the current last one, position “length+1”

I think it's confusing (not to start with, but…). I suggest this simple rewording:

“item (last) of list” = the last one, at position “length”
“insert … at (end) of list” = *after* the current last one, position “length+1”

Which (I think) is just as good for beginners, but makes sure that the word “last” is not being used for 2 different meanings.