I have some Rollei warmtone papers as well, which I believe is rebranded Foma papers. I'll try them next.
I'm using the recommended dilution found on the bottle, so I'll probably try to use less developer some time. I've seen the 15 ml a/b dilution elsewhere and will probably try it. How will the development times be affected?
There is a risk that I'll visit the darkroom for the third night in a row