Don't actually have times for you - www.digitaltruth might be worth checking.(posted 8411 days ago)I doubt that you will get the pronounced edge effects you are looking for. The reason sharpness is lacking in D76 is the high sulphite which results in some physical development - it etches away at the edges of the silver and then replates it again. As Hutchings describes it, the process results in diffused grain i.e., a grain overlaid with a more diffused portion. This, of course, is what contributes to the so called fine grain look - the spaces between the grains have been 'filled' to some extent, in a sense. It also explains why sharpness decreases because contrast, if nothing else, is going down. The dilution of solvent developers like D76 reduces the sulphite concentration so that physical development is reduced. Apparent sharpness is improved and grain also becomes a little more coarse.
However, adjacency effects are the result of controlled decomposition of the developing agent and (some say, although there is less agreement on this) reduced agitation which allows the byproducts to accumulate in the emulsion. In other words, adjacency effects are actually developing artifacts (but from the point of view of images, useful ones). In developers like D76, the sulphite is high enough to provide a protective action. Diluting it helps to reduce the solvency effects but does not really make it an acutance developer - the developer isn't really in a state of exhaustion. Further, with D76, the hydroquinone is pretty efficient at regenerating the metol, which again reduces the exhaustion and edge effects you could get. The important thing to note here is that sharpness is increasing more due to avoiding the replating etc rather than due to edge effects. Some edge effects probably can be observed with diluted developers and minimal agitation but they are unlikely to be as significant as would be observeed with a developer formulate to provide edge effects.
In sum, if you are looking for edge effects, you are better off trying a developer formulated for that purpose (FX1, FX2, Rodinal at high dilutions etc). However, if you are looking for a more pleasing balance between grain and edge effects, diluted D76 may well provide the best compromise you are looking for - a pleasing balance between fine grain and sharpness. Which look you find appealing is a personal decision.
Cheers, DJ.