This arm setup can be used in any way you can imagine. You can put up to 4 arms in the same spot, you can make your own kind of "holder" you want.

This model is made with the community remixes in mind; you can publish any kind of remix or edited version.

Specifications:

0.4mm nozzle
0.2mm layer
20-30% inffil // it changes if you are going to use physically heavy things.
Triangles or gyroid.
Almost nothing needs supports

Considerations:

You must put pressure between arms when you are about to introduce the triangular block. It is hard to introduce and take out.

Triangular blocks are really cheap to make, print as many as the print needs, dont be greedy.