Genghis_Kai
GEM modder
From a balance-based view, I guess it would not hurt. Most of the civilizations that would benefit from this are rather weak anyway (from the 1500 AD map, at least).
GEM does not have extensive coastlines - to my mind it's a map that favors land based strategies over sea based strategies. It rarely makes sense to settle coastlines only.
However, I have no idea how it could work out in other scenarios. Personally, I'd prefer to boost the financial trait itself by lowering the threshold for the bonus rather than improving ocean for all coastal civilizations, therefore supporting more diverse strategies.
Best Regards,
Ace
But I think lowering the financial trait's bonus threshold to 1 coin is a bit too much. The financial trait would almost get a +1 coin for every tile since GEM has so many rivers.