In The Hidden Church, the closest thing I can find to a personal opinion of Waite's regarding the "Lesser Hallows" is:
"I wonder that it has not occurred to some of those who have preceded me in the tortuous paths and among the pitfalls of interpretation, to understand the four Hallows after another and more highly symbolical manner, as follows: (1) The Chalice is the Cup of the Sacrament; (2) The Dish is the Paten (dish that holds the Communion wafers); (3) The (broken) Sword symbolises the Body of Christ; its fracture is the bruising for our sins and the breaking for our trespasses, while at some far distance the resoldering signifies the Resurrection; (4) In another sense, the Spear is also the wounding for our iniquities, by which the life flowed from the body, and the issue of blood therefrom is the outgoing of the divine life for our salvation. Yet it is not after this manner that we shall come into the truth of the Graal, while it is likely enough that hereabouts is one of those pits which bring the unwary to destruction."
As far as in the Graal legends themselves, he says the only Hallow that has any symbolic significance is the Cup:
"As it is in the light of man's higher part that we are able to interpret the lower, as the body is explained by the soul, so even the Castle of the Graal and the great Temple, with all their allusions and all their sacred things, are resolved into the mystery of the Cup, because there is a cloud of witnesses but one true voice which is the spokesman of all. There is obviously no need in this place--as we are concerned with the greater subjects--to lay stress upon the subsidiary Hallows as if they were an integral portion of the Holy Graal regarded symbolically. They are of the accidents only, and as such they are not vital. The Lance is important to the legends, but not otherwise than from the legendary standpoint; the Sword is also important, but not in a sacramental sense; the Dish signifies nothing, or next to nothing."
Whether or not the Lance, Sword, and Dish do actually have symbolic significance, it's interesting that for Waite they don't. That's why I think if Waite did have a view on what they represent symbolically, we have it in his quote above.
In the PKT, the Ace of Cups is the only Ace about which he comments anything more than "Hand holding a Wand," etc. I believe for Waite, the suits all represent aspects of the sacrament of the Eucharist, and the Cup encapsulates all them all.