Is it possible to add self made modules/placeholders?

Hi forum,
I am new to the modular world and i am glad that a tool like MG exists. Thank you for that one!
In case this question already came up, please submit a link. I really tried to find but i think this not a good solution for my specific case.

Yesterday i build my first custom module. Its a passive breakout board for "Arturia BeatStep PRO". Now i am wondering if this is addable in MG.
It really does not make any sense to submit this a new module because its unique.

Is there any best practice to add something like this or is this simply not possible?

Submitting is still an option for you. You just need to fill in some of the fields and then make sure to have "Do not list this module" checked. This option is tailored to your need:

Check this field if you do not want your module to be listed in the module browser. It will be excluded from the module search, too. This is useful for your unique DIY modules and alternations of modules already in the database, technically considered as duplicate.

ahhh - great
thanks a lot!