Just checking, are you aware of the exploding Ultegra crank arm issue?
https://www.bikeradar.com/news/shimano-crankset-recall
It's a serious issue with potential injuries as a result. Has happened to multiple people I know (thankfully without injuries) and I am also an owner of one of the affected cranksets.
I'm not worried about the actual failure, I'm pretty switched on and sure I will notice it before the complete failure occurs, but this could curtail or hinder a tour or cycling holiday should it happen at an inopportune moment.