Optimization of Atlas ui font size

ui Atlas size

FSlateRHIResourceManager::FSlateRHIResourceManager()
    : bExpiredResourcesNeedCleanup(false)
    , BadResourceTexture(nullptr)
    , DeleteResourcesCommand(
        TEXT("Slate.DeleteResources"),
        *LOCTEXT("CommandText_DeleteResources", "Flushes and deletes all resources created by Slate's RHI Resource Manager.").ToString(),
        FConsoleCommandDelegate::CreateRaw(this, &FSlateRHIResourceManager::DeleteBrushResourcesCommand))
{
    FCoreDelegates::OnPreExit.AddRaw(this, &FSlateRHIResourceManager::OnAppExit);
    FCoreUObjectDelegates::GetPostGarbageCollect().AddRaw(this, &FSlateRHIResourceManager::OnPostGarbageCollect);

    MaxAltasedTextureSize = FIntPoint(256, 256);
    if (GIsEditor)
    {
        AtlasSize = 2048;
    }
    else
    {
        AtlasSize = 1024;
        if (GConfig)
        {
            int32 RequestedSize = 1024;
            GConfig->GetInt(TEXT("SlateRenderer"), TEXT("TextureAtlasSize"), RequestedSize, GEngineIni);
            AtlasSize = FMath::Clamp<uint32>(RequestedSize, 0, 2048);

            int32 MaxAtlasedTextureWidth = 256;
            int32 MaxAtlasedTextureHeight = 256;
            GConfig->GetInt(TEXT("SlateRenderer"), TEXT("MaxAtlasedTextureWidth"), MaxAtlasedTextureWidth, GEngineIni);
            GConfig->GetInt(TEXT("SlateRenderer"), TEXT("MaxAtlasedTextureHeight"), MaxAtlasedTextureHeight, GEngineIni);