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@jhonerick This type of pinching artifact is generally caused by excess smoothing stress generated where edges cross over the face of a curved surface to connect the corner vertex to the support loop. In this case the effect is exacerbated by the edges of the support loops themselves because they disrupt the segment spacing of the curve and are generating some unintended surface deformation before the smoothing is even applied.

While it is possible to brute force a solution by arbitrarily increasing the geometry density of the curve, it's also possible to simplify the mesh and solve each issue individually at a higher level. Keeping the shapes relatively simple and using the existing edges in the curve as part of the support loops for the intersecting shapes is generally considered best practice when working with subdivision and allowing the subdivision do a lot more of the smoothing work will help make things easier.

Below is an example of what this could look like: Start by blocking out the basic shapes until there's enough room between the segments of the curve to accommodate the intersecting shape, plus the width of the support loop for that same shape. Work on solving the basic topology flow paths around the shape and across the curve. Use at least one of the edges in the curve to act as an intermediate support loop across the flat interior surfaces of the intersecting shapes. Route the primary loop flow paths around the intersecting shape first, avoiding unintentional deformation of the curved surface, then add the final support loops to sharpen the edges of the shapes.

The basic topology flow can be routed directly around the shape intersection with manual loop placement operations and the tighter support loops, used to define the sharp edges of the shapes, can be generated with vertext group or edge weighted beveled / chamfer modifiers. Using the existing edges of the curve as support and keeping the tighter edge loops within the existing segment spacing will help reduce undesired pinching and surface deformation.

Here's what the final base mesh looks like before and after the edge sharpening support loops + subdivision are applied.

The same basic topology routing strategy works for most types of serrations. In this example there's no space between the edges of the serration and the resulting triangle on the curve is constrained by the adjacent loops and doesn't cause any noticeable smoothing artifacts so it's acceptable.

A lot of A1's and similar variants have fairly shallow serration patterns and when dealing with details like this it's generally best to keep things as simple as possible. Let the subdivision do the smoothing. Here the same segment spacing from the previous example works with the shallower serrations.

Subdivision smoothing is an approximate process: so there's a trade off between mesh density, editability, and shape accuracy. The topology routing in this example does produce some very minor surface imperfections, however they're only visible at extreme glancing angles and when viewed up close. 

Close up comparison between reflective high gloss material and soft highlight material with smooth roll off. Subtle surface quality issues like this aren't visible under all conditions but could be resolved using the same topology routing strategies and increased segment density along the curved surface. 

With subdivision: whether or not all that extra effort makes sense depends entirely on the use case, view distance, and material reflectivity.

Depending on what the project goals are: it may also be worth looking at alternate poly modeling and re-meshing workflows (some of which are native to Blender) or maybe even a parametric modeling workflow like Fusion or Plasticity.

The example below shows how those subtle surface quality issues are largely unnoticeable at first person view distances.

Also, tighter support loops around the edges might look great up close but the edge highlights around the shapes will tend to disappear when viewed from further away. Over sharpened high poly models can also cause baking issues. Which is why it's generally better to have slightly softer edge highlights so the shapes remain readable at a distance or when baking down from a high poly to a low poly.

Recap:

-Block out the shapes and solve the larger topology flow issues first.

-Use the existing geometry of the curve to support the transitions between intersecting shapes.

-Avoid over sharpening the high poly as this can make the shapes difficult to read and might cause baking issues.

Links to additional write ups that cover similar shapes and smoothing artifacts:

@naman When modeling formed textile products it's often a lot easier to develop the basic shapes first then collapse the subdivision so there's enough starting geometry to place the seams, folds, darts, channels, tufts, etc. then use those edges as a starting point for modeling the rest of the details.

Links to some other write-ups on subdivision modeling soft goods: