Rule question regarding Blex, Vexing Pest // Search for Blex

[Akira Foxmind]

As the topic says I have a question about the ruling for Blex, Vexing Pest // Search for Blex when he is your commander.

Let's say you cast Search for Blex from the command zone, it resolves, is to be put into the graveyard but redirected to the command zone again. Would the commander tax counter be 0 or 1?
To put it a different way: is Search for Blex also expected to be a commander? (since it is not legendary)
It's a bit difficult for me to find an answer, because I think this is the first dual-faced card that can be your commander but has a non-legendary face.

[Morganator 2.0]

The card itself is still your commander, and you did cast it from the command zone. The next time you go to cast either side, you would still have to pay 2 more mana.

[Akira Foxmind]

The card itself is still your commander, and you did cast it from the command zone. The next time you go to cast either side, you would still have to pay 2 more mana.

Thanks for explaining.
Though, I'm not sure whether I like the idea of having a sorcery/instant in my command zone.