We don't use what you are seeking. For big dives, we bring safety divers who come down regardless of SMB color. For lessor dives, we have enough reserves to manage independently.
You can put a normal inflator nipple on some of the (huge) closed carter bags, but it will "lock" onto LP hoses. I don't know a source for non-locking inflator nipples, you could contact Halcyon directly.
