You deleted your comments but not the post 🤪

Depending on which slicer you use, you can probably merge them as an assembly. I use Orca Slicer and after loading a model I can then right click on it and add an STL to it. Then it’s a matter of positioning and lining them up. Once done you can slice it as one model.

Figured as much 😜

Surely that wasn’t with the stock hot end though. I’ve done 400 mm/s at 12k mm/s² but I only achieved enough flow after upgrading to a KE style hot end Proof

For simple stuff like this I’ll usually just do it in the slicer. Orca and Prusa slicer have some basic tools for this including using SVGs.

Let’s hope the ones you’re trying to sell on Etsy don’t have this same issue 😜