Well, I did reinstall Pigments and I'm back on the Splice rent-to-own plan, it does have so many awesome features and does sound really impressive.
Yeah, sorry for the tone of my post. Indeed, the OP's post wanted something else, but I think the motivation was the same as for me:
The default Arturia Pigments 2 preset is "Reverse Box". It has samples loaded, effect chains and modulations set up, and modulation sources that aren't used have values dialed in and parameters set (LFO 3, Random 2 & 3), the macro knobs have names. And there is no "init the synth" setting or preset that gets rid of all those settings.
I'm fairly sure that preset is exactly the one the OP created and wants to set as his default. I do think that this should be the default state of a synth when I open it up.
After another 90 minutes, I think I have a preset that does exactly that (unless I missed another setting). So my "Init" preset is there. And, your post further up in the thread also helped: The file presets.featured.xml in the Presets folder has a list of presets, and indeed Reverse Box is at the top. I added another line before that:
<item path="/Pigments/User/User/Init"/>
This does what the OP wanted, and what solves my problem. It looks like the default preset Pigments loads is the first from that XML.
Now when I load Pigments, my Init preset is loaded, and I have a blank canvas for creating whatever sound I can dream up. Yay! And thanks!