This series of code that mastercam outputs is a generic " put things back the way you found them" senario
It all depends on the machine and control, does you machine know it's position at boot-up or do you have to home the axes
Some machines set the "part origin" from it's current homed position. If you are not at home, how is the machine capable of setting the work datums. If you left the code "as is", what do you hope to gain--- 1/2 a second of cycle time, and 1 hour of setup grief, or do you leave it alone.
Tool change is usually at a pre-defined point, either home in Z or at a known point. Mastercam would be using a "SAFE POINT" for all the above, and it would be up to the programmer or operator to "chop" the program to gain any time for a production type job.
Single or low quantity type jobs would not be worth the effort to trim time out of it, as it would take 1/2 hour of editing to save 5 minutes of time- so it's not really worth going that direction.
Even keeping tool retracts short as possible, is not cost effective. You run the danger of a descent crunch ( the tool and or the part will end up in the
skip ). Yes, keep the retacts respectable ( say 3mm or 0.1" above the highest point )  |