As a very belated update,the YZ has its gas motor back in. Its nice how similar the handling is between the two setups. I'm not willing to add all the extra weight to get decent trail range, so I'm going to put the same electric parts in a trials chassis. The changes I made to the controller should work well for trials riding.
The YZ had almost no water protection, it would be necessary for anything ridden off road regularly. I'd expect dust to be bad for the brushes too.
It's fun building, good luck. If you're willing to get the bike up to DS or ADV weight then you'll get much better range.
The CRF looks really nice. Their packaging is impressive. Two parallel motors must be awesome, hopefully it works better for them than on the Motocycz IOM bike.