The H3000 is a high bar, especially if you’ve rolled the rectifier and tried alternative footers under the power supply. I’ve been running mine for a decade. The best rectifier I’ve found is the Riccardo Kron Anniv 5u4g. Many people like Stillpoints SS ultra footers, the smallish ones. But only under PS, which controls the overall sound to a shocking degree. They open up the highs but do compromise the midbass a bit. I just recently switched from them to CMS footers and the jury is still out.
All that said, I’ve been thinking about bringing in a transimpedance phono stage to supplement the Allnic, not replace it. Given your results, I think I won’t try the Grail. The new Mofi looks interesting.