Re: courtesy flags
Search online for the correct flags. Most 'English' islands - Grenada, St Lucia, Dominica, st Vincent and the Greanadines, Antigua, St Kitts and Nevis - are independent countries so have their own flags. There are still a few colonies like Anguilla, BVI, and Montserrat. They have a British ensign with their own coat of arms on it. Martinique, Guadeloupe, and St Martin are part of France so you use the tricolore.
Not sure where you are getting your flags. We have had good success using 12 x 18" desk flags, the kind with sticks. They will last for a month easily and only cost a bit more than $2 each - cheaper if you buy more than one for a country. You even get sticks that you can try to find a use for.
Finished the circumnavigation in early February in Grenada. Have to work on a book project for the next several months so the boat will be waiting for next year.