Yep that's exactly right :) ! To clarify my statement POSIX requires at least 8192 bytes for the pattern and hold space, and I chose to allow at most 8192 byte

Yep that's exactly right :) ! To clarify my statement POSIX requires at least 8192 bytes for the pattern and hold space, and I chose to allow at most 8192 bytes here, which indeed means that this will prevent working on really long lines or storing entire files in the hold space for instance.