Rather than having it be done individually, how about just have a certain part of a text file that turns certain leaders off if the government is a certain ideology or further? (E.g. Fascists refusing to work in a government that is Social-Democratic or beyond)
Like maybe in leader files it can be used for loyalty, like "will_not_serve=yes;stalinist;right" meaning that x leader will only appear if the government is Stalinist and if anything to the right of Stalinism (LWR, etc.) appears then he will not fight. Or you can just make it more general, like communist;right (Stalinists, Leninists, Left-Wing Radicals, anything to the right of those = will not fight for, etc.)
That way you don't need to fill in the political ideology of Glorious Driver Comrade Ismail Mukhammedov of the hypothetical Greater Kazakh Union whose footnote biography can be easily found in Velikijj kazakhskijj sil Peremestit Konsolidaciejj socializma protiv fashistskikh zakhvatchikov, Vtorojj tom (1943), but you can have Stalin only fight for the ideology named after him.
So yeah, basically what Raczynski said.