If it's possible to do so, I think the war event where the UK and France fight over Tahiti needs to be made a colonial war. I was amused to watch France turn red during the war, but a peace where the UK takes France's entire overseas empire plus part of Brittany seems wildly disproportionate to the original offense of grabbing one Pacific island (even one as nice as Tahiti

).
I'm anything but a modding expert, but I didn't see a colonial war command in event commands.txt. So perhaps the solution would be a pair of new events triggering on the Tahiti war event plus Paris or London being occupied, that would force a sensible peace (Tahiti plus money if UK wins, maybe money plus extra bonus prestige if France wins?).