Here is something that works for me and wonder how many that finish on naturals think this way too.
Escher Finishes.(any fine German water stone really) For me entering a progression to leave that wonderful edge afforded by the German Water Hone family of stone is later is better than sooner as far as where to stop on synthetics. At least an 8k starting point is best because of the slow nature of these cutters.
I cringe at the thought of someone using these endangerd species with foreign slurries and trying to stay on them any longer than needed. Yes, I too love experimentation, but these stones are precious and their supply is so limited.
Jnats. Having only 4 of these hardley makes me an expert is true, but having three of the four coming from the likes of distributors that personally selected them that are in the top of their fields gives me confidence that they represent very good quality.
All my finishers range from hard to very hard.
Method 1. Use like escher types as written above. This was my MOP for quite some time that gives great shaves and always seems to work. Very light slurries from tomonaguras or German Water Stones help on hard stones to impart a Jnat feeling edge.
Method 2. Going from Shapton 2k level which might be about a 4k level Norton and some other stones.
Use an aggresive slurry made from Jnat Tomonagura. Edge work continues until slurry breaks down evidenced by color change made by swarf. Then dilute until almost no slurry. Any of my finishers seem to be able to do this with no problem at all, maybe just a little mor time overall from above method. Edge produced imparts more of the charecter of Jnat. Aggresive but smooth also.
This stuff is really hard to quantify and to put into words, how does one describe escher edge? I believe most of us that have been around for a while know it when we feel it on our faces.