Ilford PQ Universal developer and its close cousin ID-62 have been used as the first developer in B&W reversal processing with suitable amount of halide solvent. There is a MQ precursor of ID-62 called ID-20 which used Metol in place of Phenidone. Has anyone here used ID-20 as the first developer in reversal processing? In the context of reversal processing what are its pros and cons over Ilford PQ Universal and ID-62?