I would love to know if they work - but I don't think I would be brave enough to use them.
The reason is because they are not officially supported by Meraki. So if Meraki do a firmware upgrade in a years time and they stop working - you have no recourse.
I've never used them for 10Gbe but the safest option would be to use a pair of media converts that do support this. I'm sure something exists.
I have previously used a pair of Cisco routers to handle the BiDi optics, and then run them into the Meraki kit. Everything fully supported, but that was at Gigabit speeds.
You could also consider using some low end Cisco Enterprise switches to change the media. Something in the 9200 series family would probably do the job. Will be much more expensive than media converters though.