Hey @Danidoc 
Openers are very personal, and you can definitely experiment with what works for you. The text on Truuli and other openers, like Cajon, is not meant to imply that one is useful as an opener and one is not. All of them can work and are a matter of personal preference.
However, I’ve forwarded feedback to the team that openers and their descriptions caused some confusion, so we can take a look!