I have my Assioma Duos converted to MTB SPD and used them on my MTB for like a dozen rides but kept striking them on rocks or small (~2”) tree stumps. I decided that sooner or later it was going to break them so I needed a better solution.
The Sigeyi AXO crank spider based power meter is just as accurate as my Duos in pavement riding and actually more accurate for MTB riding, since the Duos tend to count standing and pumping as power output even though cadence is zero. Plus the AXO is half the cost.
See details here. Sigeyi Power meter? - #111 by huges84