You must not alter the original title against guidelines to obtain preferential sorting that does not follow the contribution rules. Changes to main profile data will not affect the data on other devices unless contributed to the public webservice which will change it for everyone meaning it must follow the rules.

What you want is already present but I am guessing you are using the wrong approach to try and do it.

First the main profile original and sort title should always follow the contribution rules and changes to them must be contributed to be reflected on other devices, customising those against guidelines and contributing such incorrect or invalid data will ultimately attract warnings and moderator corrections.

The option you want to use is the personal sort in the personal data. This is a custom sort you can set for you only and it will sync across your devices and override the web service sort title.

It also sounds like you have the app setting prefer original title enabled which will sort items based on their original rather than sort title. If so you want to turn that off so the sort title is used and then where necessary set the personal sort in the personal data for any personal preference.