This is a wonderful graphic to show how plants and seeds should be planted on prepared, firmed plant beds. I think however you'd have to have a few different templates with differing distances between holes for seeds. Good graphic on planting starts and ornamental plants, too, but no template necessary.
For instance, if the distances between those holes were 6 inches; that template spacing would be ideal for lettuces, spinach, radishes, beets depending on variety...this pattern makes far more use of the soil of our beds than does making rows. I am unable to think of a single instance where straight rows ever make sense including hedges...grins.
Larger plants are planted in the same type of pattern; making the equilateral triangles used for ground covers and vegetables or isosceles triangles to plant ornamentals. More or less, shouldn't use exacting placements for larger plant starts, anyhoo.
I get pretty sloppy myself when planting seeds in the garden soil and I can really see this working, Sow seed by settling your template on firmed, raked soil, easily pop one or two seeds in to holes, Take a screen and shake sifted, screened soil to the correct depth over your template and holes, for the size of seed, Take a dowel and firm the soil over the seed (make sure that seed is covered correctly at the proper depth and sort of held in place by the firmed soil)... then picking up the template gently, move over a few inches to firm the entire square of seeds gently. The seed doesn't wash away as easily. And what a nice organized look to my salad bowl beds, beets, broccoli and strawberries.
It would help with knowing the seed viability as well. You'd have more assurance the seed was all planted at the correct depth, best seed/soil contact, all getting the same treatment. If only half come up you know that that seed is needing to be replaced for the next season. Or for staging smaller crops by planting every two weeks so lasts all season?
Interesting idea, Vivid...