Edit DLC ymt file

Hello,
I’m trying to create resource to add custom clothes on my server.
I found how to add new slot on the shop with modify the ymt file of heist4 DLC. But after this modification, the game loads default clothes files instead of heist4 files.

Does anyone already find how to load right files ?

Normal pant without modify the .ymt :

With my custom mp_m_freemode_01_mp_m_heist4.ymt :

Did you find any solution for this? I am facing the same problem.