Question Orient particles to the normal of their emitting vertex

Hello,
I'm having an extremely hard time doing something that appears to be simple in my mind but apparently isn't.

Ultimate goal is to have particles lay flat along the triangles of the final mesh, in the centre of each triangle (and not rotate with the camera).

I've nailed the position alright with using either

Set Position From Mesh

with a custom mesh or a pointcache (vertex) created from said custom mesh.

However, I can't get the orientation to match the normal of the vertex the particle takes the position from. I came kinda close with plugging either the normal attribute map or the direction attribute into

Orient: Advanced

.
But it appears the vertex normal changes slightly every time it's evaluated: particle orientation is never the exact same for two particles emitted from one and the same vertex.

So question: how can I orient my particles to face along the normal of "their" vertex?
Or, if any other solution comes to mind please share <3

EDIT: Additional info

• when plugged into colour directly, the normals attribute map produces slightly different results also
  
• this also happens with a pointchache generated from a standard unity sphere

 

Hi Julien,
thanks for the quick reply! You're right indeed, I forgot to set the second axis to tangent. Setting that gets me close to what I want (the particles lying flat on the faces of the mesh). Now I'd need the angle of the particles to be uniform, i.e., having the texture on the default particle all point in the same direction. As it is, on most particles the green line points into one direction (perceived "up"), but on some it randomly doesn't.
How would I go about that? Or is it something to do with my mesh normals maybe?

 

Apologies, I sent the wrong screenshot for the graph setup. This ist the current one:

 

I figured it out by trial and error XD
I won't claim to understand what's going on here, but this setup works. If you could spare the time to go into some detail as to WHY it's working, I'd really appreciate it. But you've been very helpful already, thanks a bunch!