But whether those improvements will see them genuinely contend in the Prada Cup challenger series, which starts Friday, remains to be seen.
In their first outing on NZ waters, Team UK were completely outclassed in the warm-up competition, losing all of their races and leaving many questioning the boat's credentials.
A day out from the start of racing, Sir Ben insists his wider team have made wholesale changes to their AC75 since their disastrous debut.
"We have got a new rudder, a new elevator, a new mast, a new mainsail, headsails, aero modifications to the hull and we've changed systems to the hull, so we have been quite busy," says the four-time Olympic gold medallist.
But the team's glaring and well-publicised weakness has been their inability to perform in lighter winds, and the extent of those improvements in that area will be immediately put to the test in a doubleheader against the Americans and Italians on Friday.
"We'd love to race in the stronger breezes, I think that's no secret," Sir Ben admits. "Everyone can see that and our competitors can see that.
"The trick is we can't control the weather, of course. I think we're seeing a medium breeze for Friday, and a bit lighter for Saturday and Sunday.
“We have justifiably taken quite a bit of flak for our performance and it’s been my job to protect my team from that. We have improved a lot from where we were in light airs.
“Have we improved enough? Time will tell."
Team NZ boss Grant Dalton has warned against dismissing Team UK's threat based on their world series races, insisting their skipper's quality will come to the fore when it matters most.
"You just can't write them off - it wouldn't be fair, it wouldn't be right," Dalton has told The Times. "With the talent behind that organisation, you write them off at your peril,"
"The one thing you can never dismiss or ignore is the fact that Ben is the most decorated Olympic yachtsman in history.”
Sir Ben (43) is as eager as his doubters to see the result of his team's hard work on Friday.
"I think we have come a long way down that road of improvement, but there is still more to come, as these other teams are improving every day.
"Pretty much every day they are coming with new upgrades to their boats. We are excited to see how much of a jump we have made.
"I think we can be competitive, certainly in the medium to stronger wind range. The lighter airs, we really still don’t know."
Join us on Friday for live updates of the America's Cup challenger series.