Enable better performance or better display
Enable Better Performance simplifies T-Spline geometry to improve modeling performance.
Enable Better Display returns geometry to its true shape.
Improve display
In the Design workspace, Form contextual environment, select Utilities > Enable Better Display 
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The Enable Better Display tool returns geometry to its original continuity around star points. However, modeling performance may be noticeably slower, particularly on complex models.
Improve performance
In the Design workspace, Form contextual environment, select Utilities > Enable Better Performance 
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With Enable Better Performance, regions around star points will no longer have smooth surface continuity. For complex models, this mode makes modeling tools considerably faster.