Hmmm . So I guessing that the International Warrenty isn’t that important ?
Firstly, it is a Rolex, robust and reliable, often needing no service for its first 10 years (personal experience and also many other people's)
Secondly, movements with basic complications such as a date and GMT are not difficult to service or repair.
Thirdly, and this is specific to the ca. 3186 and this is what I had read online about Rolex, in the USA anyway.
If it is the caliber 3186 jump hour and date adjustment issue in the GMT LN and also in the late model 5-digit GMTs and 16570 Explorer 2 before the switch to the super case models, Rolex will simply quietly replace the problematic component with an updated and more robust component at no charge, even after warranty. This is what I read online about Rolex service centers in the USA. Not sure about Singapore though, but safe to say Rolex do not want a class action suit on their hands, over an easily solved problem.
Rolex had then decided to replace the problematic component with the updated one across all their 3186 movements begining in 2014, both during production and during servicing. This is what I had read online.
Since the Batman GMT started production in 2014, it is safe to assume all Batmans have the upgraded 3186 inside already.
My personal experience: I have a 2015 Batman, a 2008 116713LN and a 2009 116710LN. After coming back from service, both the 713LN and 710LN click similarly to the 2015 Batman, which has never been serviced before. Previously, both the pre-2014 GMTs had a mushy feel when adjusting the jump hour hand. So they must have changed something during servicing.