Hi Marko,
I am using Bergger BPFB-18 for enlarged Pt/Pd negatives. I make first the interpositive with contact printing my original negative(4"x5") on Tmax100 developed with Rodinal. This is a flat negative (Density difference of 1,00)
This IP is then enlarged with the enlarger on the Bergger BPFB-18. I put a black cardboard on the easel to prevent back exposure. The developer I use is home made D-19 diluted 1+5 and developed for 3-5 minutes regarding the contrast range you want to have.
Any other paper developer can make the job, you have to test. The film has a very accurate responding charactere to time and dilution. If you wish, I can send you the exposure and developing charts for my system. This could give you a starting point.
"The Bergger might be the same because as it turns out Bergger is doing nothing more than rebranding other peoples materials."
A point that I don't share with the post from Peters is that Bergger is a company founded by the third generation of the first paper and film manufacturer family of France ( Dupont and later the marvellous papers from Guilleminot)
That is true that some Bergger films and papers are manufactured in Forte(Hungary) factories, but only the production facilities of this factory are used. Otherwise the emulsion coating technic and the formulations are the trade marks and secrets of Bergger company.
For B&W fiberbase papers I use Bergger Prestige VC CB or NB papers, and sometimes Forte Multigrade PW-14 papers. As I am using a Durst L-1200 with Multigraph head, I prepare offenly the contrast curves for those papers in order to enter the input values to the Multigraph head's computer. The values are totally different and you can not have the same shadow details on Forte, as you have on Bergger for the same contrast grade for both papers. There is a common opinion that Bergger is a repackaged version of other products. This is absolutely not true.
Best
Mehmet Kismet