Ok, so I created a completely new part and i am now experimenting with the optimize feed rate parameters. what I found out is that if I use nominal stepover less than 2mm, and the feed rate is set to 420, the engage movement will be 420, but then the whole feedrate is slower than 420 and even slower in the corner with cylinder, if i use nominal stepover greater than 2, the whole feed rate will be 420 but the slowdown wont be near close to 80 as i want it.
the closest i got is the 1st picture where it goes 89 in arc, but to be honest, my knowledge about NX is very limited, actually I learned a large deal just by trying out the stuff you suggested, and this method with adding extra blanks and then trying to maybe hit the feedrate you know you need, seems to me pretty time consuming.
Why I am actually trying to have a variable feedrate is becaouse as i said i work with wood and along the grain you can machine alot faster than perpendicular to grain, so i wish to save as much time as possible since i'm producing more than few of this product, and since the material is soft it tears out pretty easily in some areas, and those are the areas that i want slower feedrate, the feedrates i want are tested.
Select the top face as part boundary and click ok.
Go back to Part Boundaries --> Edit.
Here you can cycle through the selected curves using the arrows and give each an custom feed rate. (The selected curve is highlighted in orange)
Attached you can find a picture and the file.
Just confirming the blank has to be in the workpiece for Optimize Feedrate. It uses the IPW, which requires a blank in the geometry parent, not the operation.
The other approach here seems to be custom feedrates, which can be on boundaries or faces. This may work, but it will be very tedious if you want gradual slowdowns. That's why I tried the triangular blank on the corner - so the system woudl adjust the feedrate gradualy.