Maybe the Rabbi could share with us what the halakhic consideration is for using tekhelet according to the Raavad's view, and not like Maimonides or Tosafot.

Who said it has to be done like the Raavad? True, many do follow that way, since the assumption is that this also fulfills one's obligation according to Maimonides. Though on that basis Tosafot would actually be preferable, but that's expensive (the Raavad is no more expensive than Maimonides, because it's one full thread instead of half a thread—which is relatively costly because it's hard to produce).
I don't see any special halakhic depth here, if that's what you were expecting.

And I wonder…
Many articles have been written on the subject—why doesn't the Rabbi see any halakhic depth here?

I don't know what they wrote, but on the face of it there are a few views here, and that's it.

And there's no reason to decide between them?

In most cases, deciding between the views of medieval authorities (Rishonim) in Jewish law is not done on the basis of conceptual analysis, but rather on the basis of one or another rule of halakhic decision-making (the accepted practice, passive omission is preferable, rabbinic-level doubt or Torah-level doubt, customs, majority). In the overwhelming majority of cases, one does not reject the view of medieval authorities (Rishonim) on the strength of a proof from the Talmud, since the assumption is that every medieval authority can reconcile every source.
If you know of an interesting and deep consideration on this topic, I'd be happy for you to bring it up and we can discuss it.