Support FGA compatible with split-screen

### Preparation

- [x] No one has asked for this feature before in other issues (even the closed ones)

### Describe the feature

I tried using FGA in split-screen mode and found that I have to manually adjust the settings in the Game Area Mode.

Unfortunately, the maximum value (limit) for the setting is 999, while the offset for FGO in split-screen, according to the image information, is 1250.



The offset information in the image was obtained using the Pointer Location feature within my phone's Developer Options.

So, could you please raise the maximum value?

Start by locating the Game Area Mode setting that controls the offset limit, then check how split-screen FGO values are handled. Increase the maximum so the reported 1250 offset can be entered, and verify that FGA accepts the value when used in split-screen mode.

Written by the indexing model from the issue text.