When LMR option for a destination is XUDT_ENABLED then now all SCCP messages are encoded as XUDT. You need that in this case if a message is short enouph to avoid of segmenting then we need to encode it as UDT (not XUDT).
PS: But I have one suspition. When we play role an STP (SCCP transit) then it may occure when we receive UDT message and the next destination has longer SCCP address and a message does not fit UDT limitation then we need to switch to XUDT (if it is enabled by LMR). This does not concern a feature request, but let's think of this.
When LMR option for a destination is XUDT_ENABLED then now all SCCP messages are encoded as XUDT. You need that in this case if a message is short enouph to avoid of segmenting then we need to encode it as UDT (not XUDT).
PS: But I have one suspition. When we play role an STP (SCCP transit) then it may occure when we receive UDT message and the next destination has longer SCCP address and a message does not fit UDT limitation then we need to switch to XUDT (if it is enabled by LMR). This does not concern a feature request, but let's think of this.