Good Old DK-50 !
For ages it was the standard sheet developer for Kodak, then replaced by HC-110.
Dilution A for HC-110 is often similar to DK-50 straight. Dilution B often is the same as DK-50 1:1. A good starting point for development time would be HC-110 b.
It is a wonderful portrait developer, giving nicely compressed shadows, splendid midtoned, and sparkling highlights for accents. Be warned this is desirable for portraiture, and could be disastrous for some landscape work.
In the studio I first worked, we used DK-50 most of the year. In the summer months, we switched to D-76, which worked slower, and more suitable to processing film at the ambient temp of 75 degrees in the darkroom.
Even I, who thinks RODINAL AND TRI X are a match made by angels, think DK-50 isn't really so good for 35. BUT it is wonderful with Plus X in 120. It should do nice things in FP4, which has a tendency to a long straight line curve. TXP or TMY could get out of hand quickly, since they already want to have an upswept curve.
Crawley had something interesting ways to use DK-50 as an acutance developer. Check out some old ( circa 1980s ) BJP almanacs if you're interested.
Have fun.