Hi, Bill
There is another issue also, Goes back quite awhile.
If you load a file with larger Program Extents and then load a smaller file, The Program Extents don't update properly, Needing an additional Regen for a proper size view, Smaller to bigger works fine.
In 3.042.004, Looks like Program Extents is using/picking up the Arc in N200 G3 X0.2156 Y-0.0004 I0.2845 J-0.0004 in some way.
In Lathe Mode, The Stock Size with Front Tool Position selected, Isen't displaying properly eather.
Just little issues to deal with, Tool Path View is on a list for update, I Think !.
Chip