There are some such things, none have so far convinced me. Most of them are good but totally confusing.

So here is my version.
Brushes in the first row and brushes in the second row. Simply turn around to have access to both rows. With savings for water glass or other small items.

Anycubic i3 Mega

Yes

Doesn't Matter

0,40

20%

Simply print the parts and stick it together.

You can add the pillars where you want, but I recommend the front ones where I put them so that you can take the part better.