I did some digging and I found this article using xl speedboster EF to m43 with adapter
Here’s a 2021 Update: You don’t have to do this for modern speedboosters like ULTRA and XL, mine fitted perfectly on the viltrox EF to MFT with cheap ebay CY adapter (Except I had to turn the glass of speedbooster to fix infinity focus) but that’s a seperate issue.
On the Metabones some lenses might scratch the velvet side only slightly so maybe if you don’t want that you can trim the pins just slightly but not the whole way using a professional or at home with metal cutting plier.
I think author uses old gen speedboosters since it’s 2016 but I also read this post while my lens is arriving by post and I panicked a lot and this post made me panic even more having to do this to a rare lens.