I've modified the scad file from "Fitzterra" to add more customization and powerfull features, that adds:

• More shapes (Triangle and square)
• Custom size and shapes per row and cols
• Label per hole
• Allow allen key slots
• Global tolerance for holes
• More aesthetics

All holders i generate (I like them bulky), will post them here, so check the variants i put:

• 8x2 Hex Shank with Slot for allen keys.
• 6 Hex Shank + 6 Round bits with Slot for allen keys.
• WoodBits: 8 Hex Shank + 8 Round
• Spades: 14 Hex Shank Irregular slots as mine come that way

Changelog

17/04/2019:

• Added magnetic base
• Added left and right label
• Fixed label depth was 0.1mm off

12/04/2019:

• Added more shapes (pentagon, heptagon, octagon)
• Added 'holeTolerance' to Allen Key Diameter
• Added 'hexHoleDiameterIsLongDiagonal' variable: When using hex holes, specify if the diameter given is from long diagonal (1) or short diagonal (0). Tip: Short diagonals are easier to measure.