The primary limitation for surfski paddling in Costa Rica as it will be for many locations around the world is going to be the availability of surfskis. Although surfski downwinding is a rapidly growing sport around the world, the initial financial outlay is relatively expensive, particularly in remote locations that might only wish to order/ship a small number of surfskis. There is probably no lack of excellent ocean and freshwater locations for good paddling in Costa Rica. For example Lake Arenal is world famous for its winds and wind sports, but may as yet (2020) not have a single resident surfski.(??)
As of 2020 (started around 2017-2018?) there is one well established surfski trainer in Costa Rica, Dale Ponsford, who is an Epic representative. He and his family split seasons between winter in Costa Rica and summers in Hawaii. Epic Kayaks Description
Greg Redman Video with Dale
Costa Rica has plenty of good surfing. So if you do figure out how to find/get a surfski in Costa Rica you should be able to find reasonable surf breaks and/or surfing days for surfskis.