Developing the Frankenstein Variorum Project has necessitated a reconciliation of extremely divergent markup ecosystems supporting multiple editions of a single novel. The reconciliation process involves breaking or flattening the original hierarchies to prioritize units of low-level lateral intersection, points shared in common to construct “bridge” or intermediary formats for processing with automated collation via CollateX. The output from the automated collation process also serves as an intermediary format that we transform into a TEI form of stand-off parallel segmentation, in which stand-off pointing mechanisms operate like a switchboard for connecting the individual editions which can remain (for the most part) undisturbed or unmarked from the collation process. The TEI “stand-off bridge” negotiates the distinct markup ecosystems in ways that can break the “silo” effect of isolating specially encoded editions. Far from an ephemeral support structure, the stand-off bridge upholds the whole as the “spine” of the variorum project because it improves the interoperability and interchangeability of all the markup ecosystems involved. Building the stand-off bridge effectively reconstitutes the hierarchies in a way that expresses intersections essentially as a graph structure of nodes with edge pointers to comparable nodes. Our experience on the Frankenstein Variorum is consistent with other TEI projects that involve the curation of divergence, variance, and forking in text streams. Taken together, such projects illuminate how the TEI an organize textual data in ways other than an ordered hierarchy of content objects, and that the TEI can be turned to express unordered “lateral” intersections in ways that serve long-standing goals of the TEI community: interchangeability and interoperability of electronic texts. As Syd Bauman in particular has discussed, where interchangeability reflects the capacity for humans to negotiate and adapt to markup ecosystems from systematic navigation and documentation without needing to contact the encoder for help, interoperability reflects the capacity of software tools to process the markup without needing to change either it or the tools. Although we usually consider the needs of software interoperability as at odds with the richly expressive capacity of human-readable semantic interchange, this paper suggests that the TEI can be designed to prioritize the interests of both, from facilitating automated collation to generating an interlinking web interface that gives the user means to choose and change directions in navigating multiple editions as desired.