This standard was originally created for state agencies that had units operating in the field far (100+ miles in some cases) from a regional office with evidence drops or the primary evidence function. The concept was for the field officer to be able to secure evidence temporarily in a dedicated “mobile evidence storage unit” secured to the patrol vehicle until it could be delivered to a receiving facility, which could be days depending on location and case load. I have never seen this standard marked as anything but NA by any PD or SO, who usually deal with an exigent circumstances delayed submission under standard 27.15M bullet C. The last state agency I know that complied with this no longer has these units and NAs it now.
Hope that helps!
Gary Robinson
Palm Beach County SO