Each eZFlow block adds ~40 bytes to the eZPageBlockState cookie, used to save the states of the blocks (expanded collapsed).

There's a 4096 bytes per cookie limit according to http standards, in practical terms, the maximum guaranteed in browsers implementations, what means more or less 100 eZ Flow blocks.

If that meant that a single page could not have that much number of blocks, I could consider it a documentation bug and ask for an update. The problem is that eZ Will always add the block IDs to the cookie for each edited page.

If a user edits 20 pages with 5 blocks in each one, the 4096 bytes per cookie limit will be reached with the same effects of a single 100 blocks page.

In any case, I think there should be a documentation update also for this issue since there's a limit on the effective number of blocks eZ Flow can have per page.