Cheers from southern Washington!
Personally, for me, discussing proportion about Valkyries is like discussing scale about Transformers. Yes, there's an "official" reference, but it's not that great (the Sunbow chart makes up a lot of the scale relationships, and the isometric Macross linearts are often made after the fact). Personally, if the figure looks good by itself, not in regards to a screenshot or lineart, then I feel it's a good display piece. If it is made of sturdy construction, then it's a good toy as well. We're already throwing out many of the reference lineart concepts (like the flippy feet instead of slidey feet) to make this a better toy, why nitpick about a slightly different nose shape or fin shape?
BTW, I love your Lego designs, not just your Macross inspired ones, but all of them, especially the transforming designs. I love that you integrate classic themes into them, too, like the Konig Monster being in classic space colors