Android with Room and RxJava3 - Alternative to toList()?

Question

I'm having a problem with RxJava3 and Room, I have the entities and domain models as below:

AccountEntity.java

@Entity
public class AccountEntity {
    private UUID id;
    private String name;
}

Account.java

public class Account {
    private UUID id;
    private String name;
    private double balance;
    private double totalIncome;
    private double totalExpense;

    public void computeAmount(List<Transaction> transactions) {
        // Compute balance, income and expense from a list of transactions
    }
}

TransactionEntity.java

@Entity
public class TransactionEntity {
    private UUID id;
    private UUID accountId;
    private TransactionType type;
    private double amount;
}

Transaction.java

public class Transaction {
    private UUID id;
    private UUID accountId;
    private TransactionType type;
    private double amount;
}

And the DAO methods:

@Query("SELECT * FROM my_account ORDER BY last_modified_time DESC")
Flowable<List<AccountEntity>> getAllAccounts();

@Query("SELECT * FROM my_transaction WHERE account_id = :accountId")
Flowable<List<TransactionEntity>> getTransactionsByAccountId(UUID accountId);

I have a screen (Fragment) where a list of accounts is displayed with their balance, income and expense. In the ViewModel of that fragment, I set up the LiveData as below (the repositories only call DAO methods and map the entities to domain models, and they return flowable of domain models):

Flowable<List<Account>> flow1;
flow1 = accountRepository.getAllAccounts().flatMap(accounts -> {
    return Flowable.fromIterable(accounts).flatMap(account -> {
        return transactionRepository.getTransactionsByAccountId(account.getId()).map(transactions -> {
            account.computeAmount(transactions);
            return account;
        });
    })
    .toList()
    .toFlowable();
})
.doOnNext(accounts -> {
    // Do something with the emitted list of accounts
});
LiveData<List<Account>> accountList = LiveDataReactiveStreams.fromPublisher(flow1);

The problem here is, I can observe new data from both flowable sources but I have no way to get the finally emitted list of accounts because of toList(), which only emits when completed. However I have yet to come up with an idea to accomplish what I need, which is to get the list of accounts with balance, income and expense (calculated from a list of Transaction associated with each Account) and to get new data every time a change is made in either entity table (hence Flowable in both DAO methods).

How should I fix this issue? I'm quite new to RxJava so I'm not exactly familiar to all the concepts and operators. Thank you in advance.