Max number of characters for DFF allowed for Shipment Lines

Gurus,

What is the maximum number of characters allowed for creating a DFF on Shipment Lines?

We have a requirement where we store multiple LPNs from external WMS to Oracle on Shipment lines. The current LPN character length is 12 and the client plans to increase this to 20. The current max LPNs stored for one line is around 20 as per information provided but for huge orders this could be more.

So, if we assume a max LPN of 20 to be stored on one shipment line, we easily need more than 400-character capacity for the DFF. Please let me know if this is possible to achieve in any way.