Custom Key Signature displays same in bass and treble clef (same positions = different notes). Can't use 2 custom key signature in 2nd clefs. Piano

In the midst of a piece in D major there are 12 bars (32 32nd notes per bar!) where the F is naturalized. I know it's unconventional, but I want to set the key signature to show only C#, or C# + F natural. I created a custom key signature, but when I add it to the sheet (either the treble or bass clef) it is added to both clefs, and the bass clef shows E# and A-natural because the # is on the 3rd space up, i.e. C in the treble clef but E in the bass clef. Alternatively, if I set the signature to be correct for the bass clef then it ends up wrong in the treble clef. Those two variations are in the images. The same problem exists if I exclude the natural. Should this be considered a bug?