/cc @erights who has brought this issue to my attention
In the case of a ledger, maybe shortening does not matter; the whole chain is already on the ledger and does not need to be re-attached. In the case of an off-ledger ocap certificate chain, it could be very expensive to keep around the entire chain of delegations, even though this technically needs to be done without shortening. With shortening, we can keep things much smaller; if Alice has an ocap with Carol as the target, and Alice delegates this ocap to Bob, Bob could ping Carol and ask for a "shortened" chain, which preserves all caveats and also Alice's ability to revoke it.
/cc @erights who has brought this issue to my attention
In the case of a ledger, maybe shortening does not matter; the whole chain is already on the ledger and does not need to be re-attached. In the case of an off-ledger ocap certificate chain, it could be very expensive to keep around the entire chain of delegations, even though this technically needs to be done without shortening. With shortening, we can keep things much smaller; if Alice has an ocap with Carol as the target, and Alice delegates this ocap to Bob, Bob could ping Carol and ask for a "shortened" chain, which preserves all caveats and also Alice's ability to revoke it.