Custom schema and build script for Unity Addressable Groups to override packing settings per platform. (Written against Unity Addressables 1.19.19)

PlatformBuildScriptPackedMode.cs

using UnityEngine;
using UnityEditor.AddressableAssets.Build;
using UnityEditor.AddressableAssets.Build.DataBuilders;
using UnityEditor.AddressableAssets.Settings;
using UnityEditor.AddressableAssets.Settings.GroupSchemas;

// Written against Unity Addressables 1.19.19
[CreateAssetMenu( fileName = "PlatformBuildScriptPacked.asset", menuName = "Addressables/Content Builders/Platform Build Script Packed" )]
public class PlatformBuildScriptPackedMode : BuildScriptPackedMode
{
	public override string Name
	{
		get
		{
			return "Platform Build Script Packed Mode";
		}
	}

	protected override TResult BuildDataImplementation<TResult>( AddressablesDataBuilderInput builderInput )
	{
		if ( builderInput.AddressableSettings != null && builderInput.AddressableSettings.groups != null )
		{
			for ( int i = 0; i < builderInput.AddressableSettings.groups.Count; i++ )
			{
				AddressableAssetGroup assetGroup = builderInput.AddressableSettings.groups[i];

				if ( assetGroup != null )
				{
					if ( assetGroup.HasSchema<BundledAssetGroupSchema>() )
					{
						BundledAssetGroupSchema bundledAssetGroupSchema = assetGroup.GetSchema<BundledAssetGroupSchema>();

						if ( bundledAssetGroupSchema.IncludeInBuild && assetGroup.HasSchema<PlatformBundledAssetGroupSchema>() )
						{
							assetGroup.GetSchema<PlatformBundledAssetGroupSchema>().OverrideBundledAssetGroupSchema( bundledAssetGroupSchema, builderInput.Target );
						}
					}
				}
			}
		}

		TResult result;

		try
		{
			result = base.BuildDataImplementation<TResult>( builderInput );
		}
		catch ( System.Exception e )
		{
			if ( builderInput.AddressableSettings != null && builderInput.AddressableSettings.groups != null )
			{
				for ( int i = 0; i < builderInput.AddressableSettings.groups.Count; i++ )
				{
					AddressableAssetGroup assetGroup = builderInput.AddressableSettings.groups[i];

					if ( assetGroup != null )
					{
						if ( assetGroup.HasSchema<BundledAssetGroupSchema>() )
						{
							BundledAssetGroupSchema bundledAssetGroupSchema = assetGroup.GetSchema<BundledAssetGroupSchema>();

							if ( bundledAssetGroupSchema.IncludeInBuild && assetGroup.HasSchema<PlatformBundledAssetGroupSchema>() )
							{
								assetGroup.GetSchema<PlatformBundledAssetGroupSchema>().RestoreBundledAssetGroupSchema( bundledAssetGroupSchema );
							}
						}
					}
				}
			}

			throw e;
		}

		if ( builderInput.AddressableSettings != null && builderInput.AddressableSettings.groups != null )
		{
			for ( int i = 0; i < builderInput.AddressableSettings.groups.Count; i++ )
			{
				AddressableAssetGroup assetGroup = builderInput.AddressableSettings.groups[i];

				if ( assetGroup != null )
				{
					if ( assetGroup.HasSchema<BundledAssetGroupSchema>() )
					{
						BundledAssetGroupSchema bundledAssetGroupSchema = assetGroup.GetSchema<BundledAssetGroupSchema>();

						if ( bundledAssetGroupSchema.IncludeInBuild && assetGroup.HasSchema<PlatformBundledAssetGroupSchema>() )
						{
							assetGroup.GetSchema<PlatformBundledAssetGroupSchema>().RestoreBundledAssetGroupSchema( bundledAssetGroupSchema );
						}
					}
				}
			}
		}

		return result;
	}
}

PlatformBundledAssetGroupSchema.cs

using UnityEngine;
using UnityEditor;
using UnityEditor.AddressableAssets.Settings;
using UnityEditor.AddressableAssets.Settings.GroupSchemas;

// Written against Unity Addressables 1.19.19
public class PlatformBundledAssetGroupSchema : AddressableAssetGroupSchema
{
	[System.Serializable]
	public class PlatformData
	{
		public bool shouldOverride = false;
		public BundledAssetGroupSchema.BundleCompressionMode compression = BundledAssetGroupSchema.BundleCompressionMode.LZ4;
		public bool useAssetBundleCRC = true;
		public bool useAssetBundleCRCForCachedBundles = true;
		public BundledAssetGroupSchema.BundleNamingStyle bundleNaming = BundledAssetGroupSchema.BundleNamingStyle.AppendHash;
	}

	[System.Serializable]
	public class Platforms
	{
		public PlatformData Android = null;
		public PlatformData iOS = null;
		public PlatformData Standalone = null;
		public PlatformData tvOS = null;
		public PlatformData WebGL = null;

		public PlatformData Get( BuildTarget buildTarget )
		{
			switch ( buildTarget )
			{
				case BuildTarget.Android:
					return Android;

				case BuildTarget.iOS:
					return iOS;

				case BuildTarget.tvOS:
					return tvOS;

				case BuildTarget.WebGL:
					return WebGL;

				default:
					return Standalone;
			}
		}
	}

	[SerializeField]
	private Platforms platforms = null;

	private bool hasBackup = false;
	private BundledAssetGroupSchema.BundleCompressionMode backupCompression = BundledAssetGroupSchema.BundleCompressionMode.LZ4;
	private bool backupUseAssetBundleCRC = true;
	private bool backupUseAssetBundleCRCForCachedBundles = true;
	private BundledAssetGroupSchema.BundleNamingStyle backupBundleNaming = BundledAssetGroupSchema.BundleNamingStyle.AppendHash;

	public void OverrideBundledAssetGroupSchema( BundledAssetGroupSchema bundledAssetGroupSchema, BuildTarget buildTarget )
	{
		if ( bundledAssetGroupSchema != null )
		{
			hasBackup = true;
			backupCompression = bundledAssetGroupSchema.Compression;
			backupUseAssetBundleCRC = bundledAssetGroupSchema.UseAssetBundleCrc;
			backupUseAssetBundleCRCForCachedBundles = bundledAssetGroupSchema.UseAssetBundleCrcForCachedBundles;
			backupBundleNaming = bundledAssetGroupSchema.BundleNaming;

			if ( platforms != null )
			{
				PlatformData data = platforms.Get( buildTarget );

				if ( data != null && data.shouldOverride )
				{
					bundledAssetGroupSchema.Compression = data.compression;
					bundledAssetGroupSchema.UseAssetBundleCrc = data.useAssetBundleCRC;
					bundledAssetGroupSchema.UseAssetBundleCrcForCachedBundles = data.useAssetBundleCRCForCachedBundles;
					bundledAssetGroupSchema.BundleNaming = data.bundleNaming;
				}
			}
		}
	}

	public void RestoreBundledAssetGroupSchema( BundledAssetGroupSchema bundledAssetGroupSchema )
	{
		if ( hasBackup && bundledAssetGroupSchema != null )
		{
			hasBackup = false;
			bundledAssetGroupSchema.Compression = backupCompression;
			bundledAssetGroupSchema.UseAssetBundleCrc = backupUseAssetBundleCRC;
			bundledAssetGroupSchema.UseAssetBundleCrcForCachedBundles = backupUseAssetBundleCRCForCachedBundles;
			bundledAssetGroupSchema.BundleNaming = backupBundleNaming;
		}
	}
}