True that Hans devices can be sent back to mfgr.
I found that there are many approved re-inspection stations around.
If there is no SFI sticker, it may have to go back to mfgr for certification.
I had this problem as the Hans early units only had FIA stickers.
John
PS, to answer about other SFI expirations.
The rule book states dates and specifications on belts, blower restraints, arm/leg restraints and helmet dates.
As I understand something like suits are inspected for damage and servicablity, not dates.
As for H&N, I did not see any date expiration, I would have it re-certed just for peace of mind as a failure can be irreversable.