EDC 12 bit micro keychain driver - Mk5

Been tinkering with this idea since a while. Mk5 prototype here works fairly well now.
Appart of the design goal of making it super compact I also printed it in 95A TPU that any beginner printer can use without heated enclosure. No fancy PC or Carbon filament needed.
And its using 4mm bits and a 1/4" to 4mm bit adapter, all commonly found in many cheap china "precision" screwdriver sets.
The normal bits are 25mm long, double ended bits are 30mm. I can easily modify it to be 5mm wider.
However, I did not yet find a center 4mm bit holder that is deep enough to take double sided bits.
I could drill the center bitholder deeper and make it work with double sided bits, then modify the design and make it 5mm wider. But I am still looking for a way to have that without having to drill parts.

[@ewjish]

Can that hold Wiha double ended bits?

[@the5_1]

It uses 4mm bits commonly found in any cheap "precision" screwdrivers, does Wiha offer those too?
I'd actually be interested in quality ones.
The normal bits are 25mm the double ended 30mm. I can easily modify it to be 5mm wider.
But I did not yet find a center 4mm bit holder that could take double sided bits.
I will probably try to drill the center bitholder deeper and make it work with double sided bits, then modify the design and make it 5mm wider.