How Canadian battlecruisers could reshape Washington Treaty tiers

How would two surviving Canadian Tiger-type battlecruisers affect the Washington Naval Treaty?

Their capability could force negotiators to recognize Dominion capital ships in an additional treaty tier instead of fitting every navy into the historical ratios.

Unlike HMAS Australia, a Tiger-type battlecruiser could plausibly fight a Kongo and accept useful upgrades. Canada and Australia might therefore require another treaty tier beneath the principal and secondary naval powers rather than having their ships absorbed into a simple British total.