So, what is the answer ?
Personally, I cannot see the point of compulsory mask wearing whilst walking down a corridor, sitting in the atrium etc, when you can sit and eat and drink with other passengers with no masks needed at all. Plus, going ashore, no one will be masked in the local bars, museums, shops etc, so why bother.?
At the very least get back to testing immediately prior to boarding. By so doing, you will start each cruise with a relatively clean slate.