Sorry it took this long. Had a lot on my plate. I have implemented the new loan plugin on the borrow page and made updates to your installation as well. Please check the borrow2 page. I have optimized the process to be faster as well. The calculations presented in the loan offers is handle by the loan elements on the page. After the user chooses a loan, the calculations then get updated on the loan in the backend.
As Levon has mentioned you can create your own plugin to run a different set of calculations if you want to.