For future reference, as a universal solution, you can do a very simple DEF modification to split characters that change based on their palette. Make a copy of the original DEF to edit for the other mode and then edit the pal.defaults and palette keymap of each to disable the appropriate palettes.
So for example, on Gigahertz' cvsmrkarate, the stock def should have:
Pal.Defaults=4,5,6,1,2,3
;this goes at the bottom of the DEF if it doesn't have it already
[Palette Keymap]
x = 4
y = 5
z = 6
a = 1
b = 2
c = 3
x2 = 4 ;Hold Start and press button X for palette 7, etc.
y2 = 5
z2 = 6
a2 = 1
b2 = 2
c2 = 3
and your Serious Mr Karate DEF gets :
Pal.Defaults=10,11,12,7,8,9
[Palette Keymap]
x = 10
y = 11
z = 12
a = 7
b = 8
c = 9
x2 = 10 ;Hold Start and press button X for palette 7, etc.
y2 = 11
z2 = 12
a2 = 7
b2 = 8
c2 = 9
Of course, if the default palette should be 1/7, you can change the order in pal.defaults. If you want A to be default instead of X, swap that in the palette keymap. This is just an example.
This has one disadvantage in that if you have the setting enabled that allows the CPU to use random palettes, it can still pick a different mode.