Bootstrap 4 Form Generator - Run Time Implications

Hi.
I am using the Bootstrap 4 generator to generate an update form. I have created it but I have a doubt - does the generator play any role when page is rendered? Or its only role is to create a form with labels and input boxes one-time when the generator is run?
I just see the below code associated with the generator in html form tag.
dmx-generator="bootstrap4" dmx-form-type="horizontal" dmx-populate="scGetSenderDetails.data.queryDetails"

The reason I ask this is that I need to make some changes which cannot be done using the generator wizard. But I doubt if it is the right approach - generate form by wizard then modify as required.
Please help.