That will likely be an issue.
The whole point of the platform stuff is that your sprites are scaled by the exact proportion, so the sprites are physically the same size, but contain more or less data depending on the platform. Eg. a 1x and 2x sprite would be exactly the same physical size, but the 2x one would contain 2x the data.
While it is possible to change this scaling parameter to work with any arbitrary scales (its just in tk2dSystem.assetPlatforms), you'd be going into unsupported territory there - Its really hard to design in such a way that your texture sizes will scale perfectly and not misalign at different resolutions. Basically, if you changed this so your proportions are correct (you only need to care about height proportions, not width), you would have to make sure all your sprites dont shift about when you switch platform.