Have you tried just deleting the installed ENB files?
Firstly, run FH and make sure you toggle ENB off (shift + f12)
Exit FH, locate "enbseries.ini" and "d3d9.dll" in the Feralheart folder and delete them both.
Run FH, see if it will start and that ENB can no longer be toggleable.
I tested this and it seemed to work for me.