You could, but if you ever terminate the maze then it will join up the two halves... so it ought to be fairly trivial to add a modification that enforces mergin

You could, but if you ever terminate the maze then it will join up the two halves... so it ought to be fairly trivial to add a modification that enforces merging all sets periodically, or at specific points, without finalizing the maze. I went ahead and implemented it in TypeScript (https://www.npmjs.com/package/lazy-eller https://www.npmjs.com/package/lazy-eller) and that would only require a minor modification to the final row sub-algorithm to permit additional downward connections.