To gain performance you can disable the stock modelling.
If you want the stock be just one single color, instead of have a different color for every machining.
This change the rappresantation mode of the tool in the scene.
You can select between :
Is the initial color of the stock
By default , all the tread surface, are rappresented with a reserved color. You can disable this.
Is default color of thread surface
You can edit this properties through preference dialog
When you import geometries from cad file, it can happen two adjacent entity don't have exactly the same endpoint, but they have a little gap.
This can cause some problem in profile selection or toolpath generation.
To overcome this problem is possible to set the property [Entity Grouping - MAX GAP] from [Menu] -> [Preference] .