There is no a repeater field option.
As to including a repeater field, yes, you could pretty much add anything you want, depending on your skillset.
You can programmatically add to the form a couple of different ways. If it was something as simple as a single field, I would say to use the wpmem_fields filter because you only need to add the field to that single filter – it could be included for both form generation and validation/processing. However, with something like a repeater where you might need specialized processing/handling, you’d probably want to add directly to the form using wpmem_register_form_rows and handling processing with wpmem_post_register_data.
