Hi Prakhar!
I need to show old transaction types like ZLFN on SM_CRM but it is not working.
What i did to try fix this issue is bellow:
1 - Changed the channel of ZLFN as you described.
2 - Add ZLFN in DNO_CUST04
3 - Checked SU53 but no autorization issue was found.
4 - I updated 'document type' under spro point "Assign Implementation to Change Transaction Types'
Do you have any clue what is going on?
Thanks in advanced.