I think Meghan's CoA design is so lovely and well thought out. I agree re the significance of the quills (M's love of calligraphy, handwritten notes, and her career as a communicator -- which encompasses her training in International Relations, her diplomacy-related U.S. Embassy internship, her Tig lifestyle website, and her acting career). The white songbird supporter with outspread wings looks quite perfect conjoined with the British royal lion supporter.
I agree with those who have already commented about too much being queried and read into Meghan's CoA design and reveal.
As Thomas Woodcock, Garter King of Arms has said: "The Duchess of Sussex took a great interest in the design. Good heraldic design is nearly always simple and the Arms of The Duchess of Sussex stand well beside the historic beauty of the quartered British Royal Arms."
Simplicity is key, @wyevale. It surely would have been too much and quite unnecessary to try and include too many symbolic features, such as the County of Sussex-related martlets you referenced.
Meghan's CoA design is simple, straightforward and wonderfully representative. Some have have commented about the crown seeming to 'choke or strangle' the songbird. I like Osipi's way of looking at it. In any case, we should remember that one of the charitable initiatives of the Royal Foundation is Heads Together
! No choking or sundering is involved.
Plus, upon closer inspection, it seems to me that the crown is not fitted in a tight fashion that resembles choking. It's simply lovingly adorning the neck of the fair and lively songbird, whose voice will indeed be heard methinks.
A couple of humorous asides: The stuck-out tongue of the heraldic lion reminds me of young Harry inside the car naughtily sticking his tongue out at the ubiquitous press cameras. He's also famously shown doing that in a photo on BP balcony while being held in his mother's arms. Of course, I know it's simply a coincidence because the lion as represented is the way it was designed long ago to represent British royalty.
Also re the songbird supporter, I recall in their engagement interview that Harry teased Meghan about her inability to carry a tune.
OTOH, the songbird beautifully represents Meghan's strong and confident femininity, as well as perhaps the creative theatrical aspect of her career (in lieu of the awkward actor's mask). In addition, the songbird serves wonderfully as a representation of Meghan speaking out on behalf of women and girls.