Transfer Operations

I have two accounts: 1 is checking, 2nd is a loan.

When I setup the transfer it needs to be a split operation. I am not seeing how to make this work. Example: $100 payment $60 to loan principle, $40 to interest.

My current workaround is $100 transfer, then a second operation inside the loan ledger showing a charge of $40 (interest. This makes the loan account balance reconcile.

(Side note I am coming for Kmymoney had a file corruption. Started with a fresh account tree in Skrooge.)