First off, I want to say, I am speaking in reference to PvE. I have no idea if PvP works the same way or not.
Yesterday, at roughly 2PM EST, my husband and I were elated - the timer for one of those "claim and flee" griefers was finally able to be contested. (It had been our land previously, but we lost it when one of the original major flag changes went through that would have had us replacing our flags. We lost it while we were at work. Oh, well, we thought - maybe they'd build something nice and be new neighbors. Nope. They laid two foundations, a bed, and then did the same thing in a bunch of other spots on the islands. Onesie twosie claims. No big deal with losing the claim, just wish we'd lost it to somebody who wasn't a spawn blocker.) Whelp, we sat down for the long haul - the claim timer said six hours, not the 30 minutes we'd previously seen on flags. Okay, we said. That puts us at 8PM. Sure, we're both sick, but we can do this. We can alternate naps if we need to.
Around 5:30PM, when we were down to 2.5 hours left, somebody sailed through the blue circle. They weren't there very long - we asked them to park down by our base for their treasure hunting, and they did. Less than a minute in the blue circle. The flag was back up - to five hours and 47 minutes. We'd lost more than three hours of sitting and staring. But, okay, whatever. That would have us around 10:30PM. We can still do that, we can still make it work.
Around 9:30PM, the same thing happened, but not treasure hunters. Just the regular group of people who sail around looking for untended boxes, smithies, etc. Now we'd have to wait until 1-2AM EST. At this point, we said, skip it. We'll try again in the morning. There was no alternating naps at that point.
I logged in this morning at 6:07AM. The onesie twosie spawn blockers had been on. At roughly 2AM, if my math is correct. Now we'll have to wait another three days, and hope to god they don't log in, and then that nobody so much as breathes on the area.
Backstory complete, the suggestion is this: Either make it so only the owning company and their allies can defend, or make the up and down of the timer more reasonable. Somebody passing through who isn't even part of that company or their allies shouldn't reset the claim timer by hours.
Thank you for your consideration in this and similar matters.