Foma Retro Special Developer with other films

I was wondering if using Foma Retro Developer with other films besides the Foma R320 acts like a regular developer or does it add the soft effect like it does with Forma R320.

It's actually a very much more active developer - more like DK-50/ possibly even PQ universal or similar. Retro 320 is a very much softer contrast film than many on the market today and needs quite an aggressive developer. I've used it on Fomapan 400 and HP5+ & if you need a punchy neg/ contrast boost it does a good job.