If you're familiar with the Zeller paper... Was I right in believing that the approach you're using in pijul allows the use of optional deltas as Zeller's paper

If you're familiar with the Zeller paper... Was I right in believing that the approach you're using in pijul allows the use of optional deltas as Zeller's paper describes? I was planning on digging around a little more next weekend, but if you happen to know. It definitely appears to be a natural extension of the channels feature, but it isn't clear to me that you can express the actual relationship Zeller describes.