PerpNegGuider does not work with CFGZeroStar: the SamplerCustomAdvanced node throws an error 'cond_scale'. I discovered this while testing differences in an existing workflow between DualCFGGuider and PerpNegGuider, but confirmed in a simplified workflow using only native nodes:

WORKS: Load Checkpoint → CFGZeroStar → DualCFGGuider

DOES NOT WORK: Load Checkpoint → CFGZeroStar → PerpNegGuider