Thisis a good starting point (see also at the end of page 298). Even the new PWM/Ekier Chopin Edition says that the 16ths should be played together with the last triplet notes. On the other hand, when Chopin wants you to play them after the last triplet note (at the end of the Prelude), he writes double dots. By the way, I am not aware of 1/4 + 1/8 triplets in binary meter till the second half of the XIX century. That kind of rhythmic notation is not just Baroque stuff, but well into the Classical and Romantic period.