any comments advice that you folks could give me about this developer would be more than welcome.
In general terms, paper developer is pretty generic in how it's used. Mix the developer as per the instructions, you determine a suitable development time (often supplied with the developer by the manufacturer) and then use that. This is pretty much it, for any given developer.
If you don't know the 'right' development time for your paper/developer combination, keep in mind that you generally develop paper to completion, which means that you keep developing it until the image doesn't change much anymore. You can easily determine a suitable development time by developing a couple of test strips for different times and then compare the fixed & dried strips side by side. You'll notice that the shortest times yield lighter strips, but from a certain time onward they don't change much anymore. That time when they stop changing is a good time. Usually this time will be 1.5-3 minutes for FB paper, depending on the developer and dilution.
If the developer gets slow after some time (due to use or aerial oxidation), you could replenish it a bit by adding some concentrate, extend the development time or simply discard and mix a fresh batch. The latter is the most straightforward approach for consistent results.
The above is true in general for paper developers and it'll be no different for Fomatol P.
There are differences in paper developers but these are quite slight. If you have two developers at hand, try developing an identical test print in each and compare the results side by side. You'll notice that you have to look pretty hard to spot the subtle differences. It's then a matter of choice/preference whether those differences are meaningful to you.
Choice of developer can have a little more dramatic impact if you tone the print after development; the same paper may exhibit differences in how readily it tones depending on how it's developed.