There is one area where the arcs touch right angled walls. Trouble is the arcs on the curve have "vertices", when trying to "map" them onto a straight line I get sparklies. All the simple patch meshes I use are 3x3, maybe 3x5 would help here?
This is the part in question:

In yellow you can see the floor plate I use (1/16th of a circle), in light green you see the simple patch mesh that snugly joins the yellow plate and *also* has to join the straight wall in light blue. The red dots denote the areas where the sparklies will show up.
What I would need to do is move all the red dots to where the orange circle marks a vertex. Endcaps for bevel do this.
I tried manipulating/merging vertices on the light green patch, but that never worked.
Here a shot of the sample map:

Map sample, using default Q3A textures:
- aetour_r28_patches.map (d/l, use "save as" to avoid download problems)
Hopefully someone can download the map sample, fix the patch problem, and upload it?
Thanx.