I agree, lowering the number does not help the under-represented state parties that struggle to draft nominations, it only (slows) the imbalance in the list. Capping the number at 25 though however, would have some benefit for less represented countries because they would have a safe spot annually if they submitted a nomination. Like you, I would also be concerned by loopholes that over-represented continue to pursue.
I like the proposals to select priority candidates when the limit of nominations surpasses the cap of 25 nominations. This might indeed help the equity of the list.
i) nominations of properties submitted by States Parties with no properties inscribed on the List;
ii) nominations of properties submitted by States Parties having up to 3 properties inscribed on the List,
iii) nominations of properties that have been previously excluded due to the annual limit of 25 nominations and the application of these priorities,
iv) nominations of properties for natural heritage,
v) nominations of properties for mixed heritage,
vi) nominations of transboundary/transnational properties,
vii) nominations from States Parties in Africa, the Pacific and the Caribbean,
viii) nominations of properties submitted by States Parties having ratified the World Heritage Convention over during the last twenty years,
ix) nominations of properties submitted by States Parties that have not submitted nominations over the last five years or more