extensions of the root and crown chakra / Opening watchtowers.

[Therstharu]

I have been meditating for a long time, but when working on my chakras, I have always targeted my main chakras. (Of course, I also work on the 3rd eye and hip chakras) but I have never had any practice on watchtowers. I have some questions about them.

Are there watchtowers for the crown and root chakra? While reading from JoS, I saw places where the front extensions of these chakras were mentioned. I personally don't remember these chakras having front or side extensions. I don't feel them either.
When meditating on watchtowers, should I meditate only on the front and back (2) extensions of the chakras? This is how it is explained in JoS.

example:

Or should I meditate on all 4 extensions of the chakra: front, back, right and left? Does each chakra have this many extensions?

example:

 

[Power of Justice [TG]]

The hip chakras are extensions of the base chakra. Only the crown chakra doesn't have any extensions, the base has 4.