Spotted this: https://www.firstcall-photographic.co.uk/bergger-berspeed-film-developer-5-litre/p6648 - not being familiar with 'Bergger' products, the description makes it sound like a more expensive version of XTOL crossed with Microphen. Higher film speeds, and fine grain... I've not tried the 'Pancro 400' film, perhaps this developer is marketed for that product to produce good results at box speed or EI 800?
Tom
Tom