At the beginning of the semiquaver passages A includes 
in bars 151 and 153 and 
in bars 155 and 157. GE preserved the varying indications, although in bar 155 was erroneously given instead of . While proofreading FE (→EE), Chopin changed to in bars 151 and 155, and most probably he ordered the same change also in bar 153, in which FE does not have any sign (it is possible that was removed, yet one forgot to add ). Since in this type of contexts Chopin would often use both signs interchangeably, the proofreading was almost certainly meant to organise the notation and not to change the required performance.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: Errors in FE, Authentic corrections of FE,
notation: Ornaments