There is no feasibility to add more Ticket Statuses in business configuration.
SAP Cloud for Customer.
Reproducing the Issue
Go to the Business Configuration work center.
Click on Open Activity List.
Search for the activity name Tickets for Customer Support and open it.
Click on link Maintain Status .
Here it not possible to add 3 digit custom status for tickets.
Currently statuses in Ticket Status Dictionary are 2 characters long. It is not possible to create status with length more than 2 characters.
Since custom statuses start with "Z" and "Y", the range where second character in status description is letter/number has to used in your system.
It is not possible to have 3 digit custom status for ticket and this is current system behavior.
Custom Status, Ticket , KBA , 3 digits , LOD-CRM-SRP , Service Request Processing , Problem