Almost all of the Japanese tone-arms I have seen/used are designed around an alignment very close to, but not quite, Stevenson. Technics SL1600 Mk2, Audio Technica 1005 Mk2, AT-1120, Jelco SA750D, Micro Seiki 202, 505, 707.
The standard overhang for all of these is 15mm. If you use the alignment comparator tool and set the standard figures, then compare with 15.5mm overhang, you will find that the slightly larger overhang loses a little in tracing angle at start of side, but gains over everything else at end of side, which to me is more important.
And yes it is quite feasible to set overhang in increments of 0.5mm, by eye.