···5051- It should work for "CAR slices" -- contiguous narrowed partial trees that may omit content before and/or after a specific key. (CIDS referencing missing nodes at the boundaries cannot be eliminated)
5253-- It's desireable to be able to archive complete *subtrees*, so enforcing a well-formed atproto commit as the header might not be sufficient on its own. (subtrees could be stored as CAR slices so this may be unnecessary)
00540
···5051- It should work for "CAR slices" -- contiguous narrowed partial trees that may omit content before and/or after a specific key. (CIDS referencing missing nodes at the boundaries cannot be eliminated)
5253+ - It's desireable to be able to archive complete *subtrees*, so enforcing a well-formed atproto commit as the header might not be sufficient on its own. (subtrees could be stored as CAR slices so this may be unnecessary)
54+55+- It *might* be interesting to allow arbitrary sparse trees. Not sure yet.
5657+- It's not suitable for firehose commit CARs, which need to include blocks that aren't in a strict single MST.