Hey! I also just ran into this. The answers are LOL-levels of unhelpful. Here is all you need to do:

1. For Payment Account, Add a new one

2. Make it a bank account, cash on hand, and name it "shareholder loans" or whatever you want

3. Allocate expenses paid by shareholder to that account

4. When it comes to tax time, you accountant will say, "hey, there's a shareholder loan account grouped with the bank accounts - I'll just move that over to equity for tax purposes", and that's all they will have to do

Hope that helps! I should look into if Intuit will pay me for actual answers...