Speedboster On BMC 2.5K?

I have OG Blackmagic cinema camera 2.5K MFT I am not stopped on what lenses to purchase I already own set of yashica ML prime, I am thinking of getting rid of them since they are to soft amd crop factor and purchasing metabones speedboster ef 0.64 or 0.59 original pocket speedboster I believe it can fit on my camera even thought it was design for pocket to go with sigma 18-35 1.8my question. Now I can also go with meike mft lenses for the price of SB and sigma I can get 2 meike mft cinema lenses 9mm and 25 what would you guys do in my case here. I am hobbyist shooting narrative content

Thanks