I try with:

'with _C in name'
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OverrideNamedEngramEntries=(EngramClassName="EngramEntry_CKF_Blacksmith_C",EngramHidden=True,EngramPointsCost=0,EngramLevelRequirement=0,RemoveEngramPreReq=False)

without _C (i see in a discussion the engran name is without _C)
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OverrideNamedEngramEntries=(EngramClassName="EngramEntry_CKF_Blacksmith",EngramHidden=True,EngramPointsCost=0,EngramLevelRequirement=0,RemoveEngramPreReq=False)

without _C and a 2000 lvl req
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OverrideNamedEngramEntries=(EngramClassName="EngramEntry_CKF_Blacksmith",EngramHidden=True,EngramPointsCost=0,EngramLevelRequirement=2000,RemoveEngramPreReq=False)

without _C, hidden false, high point cost and high level req
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OverrideNamedEngramEntries=(EngramClassName="EngramEntry_CKF_Blacksmith",EngramHidden=false,EngramPointsCost=1000000,EngramLevelRequirement=2000,RemoveEngramPreReq=False)


and all time engram is revealed, lvl 20 req and 1 point cost.

I want to use it for a rpg server, but i need to block mod only for certain purposes, not for all players.

Excuse my english, and thanks