Unwanted buckling when warping with bulge shape

[Boldline]

Using the Bulge Warp tool with an extreme negative amount applied, some of the letters begin to buckle. Is this how it's supposed to be? In my mind I expected them to remain straight.

The image below shows a simple bulge amount and then a more extreme

[b77]

@Boldline Disable 'Subdivisions' and enable 'Keep Lines' here:

[VectorStyler]

@Boldline Changing the Warp options as suggested by @b77 should fix this. I will check if the defaults can be improved.