Access of ABAPer to SE38in Production Environment

Our ABAPer is requesting to grant SE38 on permanent basis in Production Environment to facilitate him to view the source code in production and perform debugging on production on regular basis. Kindly advice:

Is there any harm in granting such access to the ABAPER on production on regular basis.

Would there be any impact on our production system for any activity performed by the ABAPER in production provided that the Scc4 is non-modifiable?