h3o they are typically used as a replacement for a DE
Sounds a bit like building a computer by selecting a motherboard, processor, memory, and other components, so you end up with exactly what you want, instead of just buying someone else's idea of a computer. I've done that a dozen or so times, so I understand the concept pretty well.
But I'm still confused about what you do with your DE. How do you get rid of it in order to replace it? It's hard for me to grasp the idea of installing Solus without one of the four DEs that are offered. Let's say I create a Budgie VM with the intention of exploring the window manager concept. How would I substitute i3, for Budgie, for example?
Just install it and select it at login?