I like the MI Audio Crunch box too, but rather for light to medium gain sounds. As well as Boss OD-3, a modded BD-2, Ibanez MT-10 (PPCB Oxyde distortion). GCI Bass Brutalist sounds really good too.
For high gain sounds, i keep coming back to the DOD punkifier (PPCB Pacifier) before a Boss GE-7 EQ, or some preamp circuit (Aion's Beta preamp = Sunn Beta Bass/Lead, or Catalinbread 5F6 = PPCB tweedman overdrive).
With the Punkifier, I really like the possibility to dial a bit of fuzziness into the distorted sounds. I think the distortion section is based on the DOD 250, I don't know about the Fuzz section, Trying many transistors for the fuzz section is worthwhile in this circuit, it's the only way to find the "perfect" fuzz texture to mix with the distortion. The stock transistor didn't suit my tastes, it was too strong and too synthetic. I use a 2N2369A instead, with lower hfe, perfect to add some dirt to the dirt.
When i want even more gain and compression, going into the crazy fuzz zone, i often use Zvex Fuzz Factory, with or without some noisegate after it. It's the most brutal and yet still musical fuzz i know. Arkaim was one of my first PPCB build, it's great but i don't like the gain texture so much. It's a bit raw and lo-fi, not as much usable and musical as the Fuzz Factory, in my opinion. There isn't any PPCB project for the Zvex fuzz factory, but Aion and musikding did it.
Frantone Cream Puff and Big Muff op-amp are a bit similar to each other, and are very impressive too. Both are great, just a little bit less interesting than the fuzz Factory in my opinion, but they have their own creamy character. The Fuzz Factory can't easily do the same thing.
For cold high gain tones with lots of sharpness, Wampler Abasi Pathos is the most suited circuit I built. It's an emulation of Mesa triple rectifier, known as Pathogen at PPCB.
For warmer and fatter high gain tones, i often use the BE-OD (PPCB thermionic distortion) or Wampler Velvet Fuzz with some mods (PPCB Corduroy). An Orange/Matamp amp head emulation would be fine for this job too, it's available at GCI, it's called Apostle.
For people looking for something more singular and original, i can recommend Guyatone Distotion H, with 5-bands EQ and a very interesting gain texture :
https://dirtboxlayouts.blogspot.com/2021/10/guyatone-ps-024-distortion-h.html
I was just curious about the Graphic EQ chip, but the stompbox itself sounds amazing, EQ is really good. I was disappointed at first, but something was wrong on my build. Once everything was fixed, I finally understood what a great circuit this is.
As a booster, i use a guyatone PS-20 bass compressor clone (Aion's Meridian) because it allows me to shape the bass, the attack presence, and dial the odd/even order harmonics to my taste, even with guitars. If I need more boost, a modded boss BD-2 (Aion's Sapphire with the extra bass control) will do better than everything else i tried. Hudson Broadcast (PPCB Simulcast) is also interesting as a booster, but not as tweakable as Aion's BD-2 modded clone.