In AcyMailing Enterprise, you can add extra fields to your subscription form to the user profile on the front-end and on the back-end. You can import users with those fields and export the extra fields as well. You will then be able to include these fields in a Newsletter. This system should meet most of your needs and enable you to create personal subscription form. If you want to personalize more your subscription form, you can still integrate AcyMailing with a Form component using the subscription via URL.
To manage your custom fields you'll have to log in your back-end and then go to the menu Custom Fields.
The first time you go to this page if you didn't run a v5 migration before you should have 2 fields listed: name and email.
As you can see they are several actions we can do on this listing.
The first one is ordering your fields, for example if you want the receiver to put this email before his name you'll have to drag and drop the field like this:
On the left of each field there are many toggle:
Required: if the field is required in front-end form
Active: if the field is visible on the user profile
Back-end profile: if you can see the field on the user profil in the back-end
Back-end listing: if you can see the field value on the user listing in the back-end