Open input.settings in Document/The Witcher3 and paste these to the start
[Exploration]
IK_4=(Action=ToggleRoachWeapCarry)
IK_5=(Action=ToggleRoachWeap2Carry)
IK_6=(Action=ToggleRoachWeap3Carry)
[Horse]
IK_4=(Action=ToggleRoachWeapCarry)
IK_5=(Action=ToggleRoachWeap2Carry)
IK_6=(Action=ToggleRoachWeap3Carry)