Light blue tassel

Perhaps the rabbi will share with us what the halachic consideration is for imposing a blue veil according to the method of the Raavd, and not according to the Rambam, or the Ketos.

Who said that you have to cast a rabbinate? Indeed, many people do this, since the assumption is that this is how you get a rabbinate, even according to the Rambam. Although according to this, it would be better to cast a rabbinate, but it is expensive (the rabbinate is not more expensive than the Rambam because it is a whole wick instead of a half wick, which is relatively expensive because of the difficulty of producing it).
I don't see any special halachic depth here, if that's what you were expecting.

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

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

And there's no point in deciding between them?

In most cases, the decision between Rishonim methods in Halacha is not made based on theoretical considerations but on considerations of one or another rule of jurisprudence (Sugain Da'elma, Shoa't is preferable, doubt of rabbinic or Torah, customs, majority). In the vast majority of cases, one does not reject a Rishonim method based on evidence from the Gemara, since the assumption is that every Rishonim manages to reconcile every source.
If you know of an interesting and profound consideration on the subject, I would be happy if you brought it up and we could discuss it.