Hi Christian,
hopefully you were not hurt 
I do agree with your diagnosis, but not with the details which you collected from the Strida manual!
I’m sure there’s no heating required.
Also I’m sure that Ming cycle never used threadlocker of high strength (which TL-70 has) - for our bikes is middle strength (BLUE Loctite 243 for example) fully sufficient.
I would not do that.
The older manual version ((Strida manual-0617 revised) said 20 - 25 Nm for this bolts.
Look, we have here (most likely) a M8 bolt with strength class 8.8 or worse.
Standard torques for this bolts are usually ~ 25 Nm - just check with any torque listing.
Kind regards,
Chris