Hi there,
I will post it up to m y thingiverse , time permitting…
But here is a ZIP file of the edited , printable parts for Grove Expansion Board Holder.
- Added Feet
- upsized the Sides
- made a front cover
- added some Seeed
END_CAP_Xiao_Grove.zip (1.7 MB)
Xiao_expansion_grove_base_End_cover.zip (609.7 KB)
HTH
GL 
PJ 
Get you some Seeed Green PLA + and have a go at it.
You can adjust size in the slicer too. the Freecad files are there as well. ENJOY 