I found the referenced 2x2 (ish) Gridfinity holder for the Dremel 575 right angle attachment (which can be found at https://www.printables.com/model/251598-gridfinity-holder-for-dremel-right-angle-attachmen)  and the related 1x1 rear mount nut holder (which can be found at https://www.printables.com/model/251606-gridfinity-holder-for-dremel-right-angle-attachmen), but realized that my kit came with two different collet nuts. and the original design only allows for a single, installed nut.

I pulled the two related parts into a single .3mf file for ease of printing and modified the right angle tool holder to include two shallow round wells to hold additional collet nuts without giving up an Gridfinity space elsewhere.