Travel insurance requirement for Schengen visa

We are citizens of the USA and are preparing our applications for our D7 visas. Most of the requirements are reasonably easy to figure out, but we are unsure about when we should start the travel insurance and for how long it needs to be in effect. We plan to use AXA as we are in our 70s. Any help or comments appreciated

Travel insurance should begin on the date your visa starts (the date you give VFS as your departure) and continue until your SEF appointment. (Approximately 4 months)

My recommendation is to use the travel insurance from the bank you have your bank accounts in Portugal, they offer this service and it’s Portuguese so you’ll never have any trouble in making claims if you need to as you’ll know the bank manager directly