To reproduce:
1. On one machine have only Android support installed and on another one have only iOS support installed
2. Create a new Unity project
3. On both machines set build targets for iOS and Android respectively
4. On Android machine create a Square sprite in the Project window
5. In the inspector of sprite import settings set Max Size to any size, i.e. 32
6. Push the project to collaborate
7. Download the project on another machine
8. In the import settings of the sprite of the second machine set Max Size to 64
9. Push the changes to collab
10. In the inspector of sprite import settings observe as the Max Size is changed correctly
11. Open Square.asset meta file and observe:

buildTarget: DefaultTexturePlatform
maxTextureSize: 64
buildTarget: Standalone
maxTextureSize: 64
buildTarget: Android
maxTextureSize: 32
buildTarget: iPhone
maxTextureSize: 64

that according to META file android actual Max Size is 32, not 64
12. Repeat the changes and observe that the machine that does not have the support installed, its Max size is not changing

Expected result: meta files on both machines are the same
Actual result: meta files are not updating Max Size of the platform that is not installed on the machine

Reproduced on: 2017.1.3f1 2017.3.1p1 2018.1.0b10

Workaround: re-set Max Size on the machine that Max Size incorrectly stored in meta file

Notes: because of this trying to build on another machine may result in bad textures and artifacts because of the meta files store incorrect information, even though in the inspector it shows as the correct. Having thousands of textures and re-setting all texture sizes to make them correct again may disturb workflow of big projects.