Just a note... but isn't Fyjgla 10 still far?
And while its nice to have info about what we can do with it beforehand... i would like to see the actual options for that.
Just noting this here, the shield swap is something ANY fylgja can do, not an owl exclusive. Hall's has a blinkdog, after all.
While Binding it with the Nordic Plate is interesting, i think that would be the same as the fylgjaskin option Halr had. Which would boost the shield/weapon swap trick, i assume, not to mention the extra armor... but i don't really like it, for Halla at least.
The glasses idea is interesting as well, would probably boost perception, yeah... but i think this would be either a variant or just something the fjlgjaskin would do anyways.
I just don't want our fyjgla to lose its freedom because that would take away its main perk, The Owl Gatcha. this is a wonderful thing. but if the fylgja is fixed as an armor/skin, it can not leave our side.
Now, the smithing... that, i could see survive if its fixed in any form, but it would probably transform into a big bonus, instead of an extra action if we go the fylgjaskin path, what with it not being able to leave us.
As for making it into an even bigger owl... while we know it could be done what with Barki Bertholdsson serving under Folkmarr, i think its current person size is more than enough.
Then, there is the skill enhancer/synergizer like Steinarr did with his rockhound.
TL,DR: While the shield swap is nice, its not revelant for fylgja development choices so log as our fylgja can access our soul.
The main concert is if we turn it into:
1) An even bigger owl, so it can be used as transport, ala Barki express.
2) fyjglaskin as Halr show us, losing its freedom for extra protection (and probably more direct access for its powers).
3) enhance a skill like Steinarr did.
4) Whatever other options exist.
So far, only those three were shown, i think. The spying through the fyjgla can be done by any type, even without specialization, so not ant specific.