All quotes are from RCV's response.

"On the other hand, QBO is unable to connect a loan account through the Banking menu. For recording a payment made from a line of credit to a vendor, we enter the transactions manually."

Payments made directly to a vendor using a line of credit cannot be recorded at all in QBO as far as I am aware.  For example:

• A purchase order is created.
• The contents of the purchase order are copied to a bill.  
• If I attempt to mark the bill as paid, I cannot select the line of credit account as the payment account.

...But I can select a credit card account as as the payment account.  Why does QBO treat credit cards and other current liability accounts differently?!  Credit cards accounts are current liability accounts.  ALL current liability accounts need to be treated THE SAME.

"To record a payment to your line of credit, just follow the steps in this article: https://quickbooks.intuit.com/learn-support/en-us/bank-feeds/record-a-payment-to-your-line-of-credit...."

Noted.  That said, the issues at hand do not pertain to making payments to LOC accounts.

"Since funds are transferred from the bank providing credit directly to a third party, it would be best to contact your accountant. They'll help you on how to best handle this one in your account. They'll also guide you with other ways on how to record the draw taken against a line of credit."

I am the accountant for my company.  The issues at hand have nothing to do with accounting; they solely pertain to issues with the QBO software.  Why should I contact an outside accountant regarding an issue with Intuit software?

I maintain that QBO's inability to process bank feeds for any type of current liability account is not acceptable.  There is no technical difference between a bank feed for a LOC account or a bank feed for a credit card account.  The fix should be simple to implement and should be available in ALL versions of QBO. Please pass the message on to your development team.

It's incredibly frustrating that Intuit continues to increase the price of QBO software when QBO is missing core financial accounting software features.