Pre-Enrollment while waiting for Admission Acceptance. DoV?

So I had received admission acceptance to Unibo for a Masters program as a non-eu student. However, my top program is at Uni Milano and I did the entrance exam on Monday. I assume I will hear back in a week or so. I have some questions regarding pre-enrollment, DoV (Dichiarazione di Valore), and visa requirements.

1. Would it be wise to pre-enroll to Unibo asap with the admission email screenshot, and my other requirements for pre-enrollment, and withdraw if I get accepted to Unimi?

2. Do I need a completed DoV to pre-enroll? I am in the process of this and was told by a US consulate that my DoV would be sent from the education office to the visa office once it’s complete. So I wont have it until I have my visa appointment (end of june), I’m assuming.

3. Am i meant to submit my DoV when I do preenrollment? Do i need to do pre-enrollment to submit my DoV?

4. Can I do my DoV by inputting the UniBo program on the request form and still enroll later in Unimilano if I decide to, and still be valid?

I have not been able to get to the payment portal on CIMEA the past few times, but my country is recognized by the hague convention and only one or the other is required for both unibo or unimi, i believe.

Thanks for any clarification. Theres so much to keep track of.