you can make another comment entry on the main post after getting two valid replies from different accounts on your first comment on the main comment, isn't it?

It is closed, there is just a simple element to correct and additional information to precise.
Your C2 under the main post comes after at least two valid entries both under the main post and after your C1.
Your C valid entries should contain an answer to the previous author's question then your message plus your personal question to the following author. Of course, don't forget the C + adequate number.
Peace