A couple of things to note:
- You can convert the Assioma’s to SPD’s with some specific pedal bodies. A Wild idea for Favero Assioma pedals [MTB SPD Hack] - #23 by rocourteau
- Assioma have teased a new Shimano pedal body for release in July
Confirmed: Shimano-compatible Favero Assioma power meter pedals are on the way - CyclingTips Unknown at this stage whether this will be SPD-SL (road) only, or SPD (MTB) as well.