It's a simple tweak, and I've posted it numerous times. Others knew of it prior to me. It's simply Perceptol used at 1:3 dilution rather than the typical 1:1, which allows for longer development time leading to more grain growth. The effect is quite different from regular dilution. But it does the same whether buying the A&B powder packets from Ilford or a home brew of the same. In the latter case, always use real sodium chloride rather than table salt, which contains adulterants.
Because this Perceptol dilution is semi-compensating, you get highlight control reminiscent of pyro - not quite as strong, but reasonably effective, at least in this day and age of highly cooperative VC papers. PMK pyro does wonderful things for TMX in terms of highlight gradation, but can't improve the weak edge effect by itself. I had to resort to supplemental unsharp masking, with its slight "halo" around edges. Now I still sometimes mask TMax films, but for a different reason, mainly to expand microtonality in the print. Developed some TMX masks yesterday in fact.