E2E Test Selection:
The changes in Engine.ts refactor the getTotalEvmFiatAccountBalance method to use Redux selectors from assets-migration instead of directly accessing controller state. This is a significant architectural change:

1. What changed: The method now reads from the Redux store via createDeepEqualSelector selectors (getCurrencyRateControllerCurrentCurrency, getAccountTrackerControllerAccountsByChainId, getTokenRatesControllerMarketData, getTokensControllerAllTokens, getTokenBalancesControllerTokenBalances) instead of directly from controller instances.

2. Why it's high risk: The assets-migration selectors are feature-flag-gated (via selectIsAssetsUnifyStateEnabled). When the flag is enabled, they return data from the new unified AssetsController instead of legacy controllers. This means balance calculations could return different values depending on the feature flag state, potentially affecting all surfaces that display EVM balances.

3. Affected surfaces:

   • SmokeConfirmations: useAccountInfo.ts calls getTotalEvmFiatAccountBalance() directly for account info rows in confirmation screens (personal_sign, typed data, contract interactions, etc.)
   • SmokeWalletPlatform: useMultichainBalances/utils.ts calls this for wallet home balance display and transaction history
   • SmokeAccounts: useAccounts hook uses this for account selector balance display
   • SmokeSwap: BridgeView uses this balance calculation
   • SmokeStake: Staking confirmation screens use this balance

4. Test file changes: Engine.test.ts was updated to mock store.getState instead of passing state directly to Engine.init, confirming the architectural shift to Redux-based state reading.

5. Dependent tags: SmokeSwap and SmokeStake require SmokeConfirmations per tag descriptions (already included).

Performance Test Selection:
The refactoring changes direct controller state access to Redux selectors using createDeepEqualSelector. This introduces selector memoization overhead and potentially changes the data flow for balance calculations. @PerformanceAssetLoading is relevant because token balances, currency rates, and market data are now fetched via selectors from Redux store rather than directly from controllers - this could affect balance loading times. @PerformanceAccountList is relevant because the account selector uses getTotalEvmFiatAccountBalance for each account's balance display, and the new selector-based approach with deep equality checks could impact rendering performance when many accounts are displayed.