Array modifier + curve modifier - Problem merging first-last - 2.72b

I’m having a problem with the array modifier where checking merge first-last option does not seem to work.

I’m using a bezier circle as the curve object. On the curve object, both stretch and bounds-clamp are checked so the mesh being arrayed to the curve automatically scales and changes count to wrap around the circle with minimal deformation.

All the other seams merge and things line up, but the first and last (end) doesn’t. This forces me to have to apply the modifiers and box-select and remove doubles, however that defeats the flexibility of being able to use the modifiers.

Modifiers take effect in top-to-bottom order in the modifier stack. Array modifier has no idea about the Curve modifier that follows it, and thus it wouldn’t merge those vertices that are brought together by the curve. Unfortunately, there is no “remove doubles” modifier in Blender that could be added after that Curve modifier.

As a workaround, you could perform bending with the Array modifier itself, by using its Object Offset option. You’d need to move the geometry in edit mode to a given radius, then in object mode place an Empty at the object’s origin. On the object, disable the Relative Offset, enable Object Offset and set that Empty as the object. Now you can rotate the empty to set the angle offset between each segments of the array, and all the merge options would work.

Shame the curve modifier has no way to weld either. (Or at least make use of info passed on via array internally to do that extra step.) Offset doesn’t quite do what I’d like to do in a dynamic fashion, it’s also case limited - doesn’t work if I decide to do something other than a circle.

I suppose I could try my luck requesting a plugin for a modifier that merges doubles or overlap in a set radius.

Even with Shift-Alt adjustments it’s darn sensitive and tends to rather leave gap of one. Considering Skin modifier also suffers some rather unusual instability i wonder if there were some changes around.

The weld modifier has been added to Blender 2.8.
So you can now connect the start/end vertexes of the curve modifier in this way.