How to Add More Than 3 Logic Fields in Bookly’s First Step?

I’m currently evaluating Bookly for a client who needs to collect five fields at the very first step of the booking process. These fields are not just for collecting information; they determine what’s shown in the following steps.

From what I can see, the plugin currently supports three fields at that stage. I’ve reviewed the Custom Fields add-on, but that seems to apply only to the Details step and not the initial service selection step.

Could you please confirm:

1. Is there a way to add more than 3 logic-based fields in the initial step?

2. If not natively supported, is there any documentation or filter/hooks that would allow us to extend this step with custom logic?

Thanks in advance!