Iceland Schengen visa

Hi everyone,

Background: I am a 25-year-old female with Chinese citizenship and a US permanent resident extension letter valid until 1/1/2025. In 2018, I had a Schengen visa for 3 months with multi-entry.

Travel plan: My boyfriend (a US permanent resident) and I plan to visit Iceland from 5/11-22 and have made an appointment with the Icelandic consulate in New York.

We are planning to apply for a multi-entry visa with at least a 3-month length and would like to know if booking another trip to Iceland or other Schengen countries could strengthen our case.

If so, in addition to hotel bookings and flight confirmations, do we need to purchase travel insurance for the entire duration of our stay from the first entry to exit date? Also, in the application form, how should we populate the number of days we are planning to stay in the region? (Initial trip or the sum of both trips)

Thank you so much for your help!