UPDATE: PLEASE READ, FOR THOSE WHO WANT TO USE IT!

I encountered an outfit problem that clips the feet and shoes below the ground. I've contacted the creator about this and this was their reply:

TO ALIGN THE SHOES WITH THE FLOATING FEET

Go the Nagi's body in the hierarchy > Blendshapes > Set "toe_highheel" to 100.

FOR THE SHOES TO STOP CLIPPING INTO THE GROUND ON VRC

Check out this FloorAdjuster on BOOTH
OR Go to this website: https://vpm.narazaka.net/ and just search for Floor Adjuster. Click Add to VCC. Once added and confirmed that it is in your project file, click on Nagi's main armature Click Add Component > Floor Adjuster And then, just set a numerical value for the height.

Personally, I did trial and error on this one but I found 0.040 to be the perfect value. After that, the clipping issue was fixed. Hope this helps!

Here