Is there a way to show reconciled transactions on the check register? Matched synced transactions could have a check mark or dot in my register. That would be handy!

Yes, let's filter the Reconcile status to show the reconciled transactions on your check register, @LRBCORP. This way, you'll be able to identify the check marks for your matched synced transactions. Please first make sure to log into your QuickBooks Online (QBO) account as an admin. Once done, perform the handy steps below.

1. Go to Accounting from the left menu.
2. Select Chart of Accounts.
3. Locate your account. 
4. Click View register from the Action column.
5. Tick the Filter icon. 
6. Choose Reconciled in the Reconcile status drop-down. 
7. Set the date range. 
8. Hit Apply. 

The screenshot below shows you the last four steps. It also displays how the Square icon indicates whether your transactions are added or matched in the account's bank feeds. For the detailed instructions, see Filter your transactions under Step 1 through this article: Find, Review, And Edit Transactions In Account Registers. 

As always, I'd suggest running the reconciliation report since you've already reconciled your account. It helps you review your beginning, ending balances, cleared, and uncleared transactions during that period. You can also print, export, and send it to your accountant to verify the transactions. Doing so will help ensure the account in QBO matches your bank statement monthly. 

I'll be right here to help if you need anything else. Enjoy the rest of your day, @LRBCORP.