Vincent, here are some pictures I took this morning of my handlebar bag and light set up.
If you go with the handlebar bag, you will need to move your light onto a front rack (as I did with my Full FatSix, as well as on my Specialized Fatboy). Or.....if your Haibike has a hole in the fork crown, there are light mounts available to mount it there. The two legs of that Ortlieb mount are set as low as it will mount. I wound up playing with the angle of the display as well as the fore and aft adjustment to move it closer to the bag.
The placement of my Schmidt Edelux II light on the front rack places the light in a line close enough to where it would go on the fork crown. That fork crown location is where German bike lighting laws specify; I don't know if this law was changed as many ebikes have lights on the handlebars these days, but since we are in the US, that is not for us to worry about.
Peter White Cycles is the definitive word about bicycle lighting. Here's the link to his page just on mounting the front lights:
https://www.peterwhitecycles.com/light-mounts.php
I mounted my front light on the Old Man Mountain rack using Supernova's bike light mount, a sturdy, well built, anodized aluminum mount that can hold it's position no matter the jarring you give the front wheel.
My lighting system is a dyno hub system. I wanted full voltage going to the motor drive and motor drive only. It was an expensive adventure, but it will last a lifetime. All Schmidt components, from the headlight, rear tail light and the 150mm rock shox bluto compatible Schmidt dyno hub. Looking forward to what you come up with....
