Doubt about how I sould generate gerbers for a board with internal cut-outs

[senso]

Good evening, here I'm again bothering you..
So a friend of mine asked for some help to make some wierd shaped pcb's with some internal cut-outs, I have never made such a thing and I would like to know if there should be extra care when generating the gerbers.
More precisely, when I generate the gerbers there is no milling paths in the drill files, only the drills for the vias.
A couple images might help me explain better, in green is the top cooper and purple is the drill file:


I can see that all the information about the form of the pcb is in the layers gerbers but not in the drill files.

[8086]

This is when you contact the manufacturer and explain your requirements to them. They can generally work out how to use the gerbers to do it, you just have to indicate which parts you want removed.

[Psi]

When i add cutouts I ...
- Put the cutouts on the mechanical layer along with the board outline.
- Add a JPG to the gerber zip file which shows the board in 3D and makes it obvious where the holes are.
- Write the number of cutouts in the "special requirements" box when submitting board to pcb house

[free_electron]

board contour and cutouts should be defined on the keepout layer.
then simply specify that the keepout layer holds the milling.
that;s it.

[envisionelec]

I convert two separate layers to v-score and routing information, create a README.txt that defines each layer plus mirroring and negative layers. If it's not very clear what I'm trying to do, I also add notes on another layer to be read by the PCB entry technician. I've never had a problem in 15 years.