Experience with Manufacturing Embedded Toroid Transformers in PCB Applications

I'm an EE student currently in a co-op position and I'm looking into the topic of embedded magnetics (specifically, a fully embedded transformer) to replace a transformer that is in one of my company's products.
So far, I've done a lot of research on planar transformers and embedded toroid transformers. While I have a good understanding of the steps involved, I was wondering if there anyone has had any experience in manufacturing this technology into one of their applications, specifically for a toroid transformer?
I've seen some images (and read some documents) that mention the PCB needs to be milled and/or cut to accommodate the toroid during manufacturing. While I haven't done anything in terms of a layout, it seems 'easy' enough to design some traces with plated through-holes connecting various layers. However, since this manufacturing still seems like a complex process, I'm hoping someone has already done this and is willing to help provide advice for any Do's and Don't's associated with this manufacturing.
I have contacted our main board shop as well, but I thought I'd try a forum as well!Please see the sample image attached. I'm hoping to manufacture something similar to this.Thank you for your time.

Too many things not mentioned to give any sort of sensible answer. What sort of voltages, currents, power, frequency and application are you talking about. What you are proposing requires that the core be embedded as part of the PCB multilayer manufacturing process. This limits core size, and probably requires a custom core, and may have many other implications that your PCB fabricator could answer. Additionally, failure of the windings would probably mean a complete board replacement. What I have done is used planar cores that fit through the PCB after manufacturing, but like all transformer design, this structure has a number of limitations that you will not be encounter in more conventional transformer winding, and its application is severley limited in comparrison.Cheers,Richard

Hi Richard,
Thank you for reaching out and taking the time to reply. Regarding my application, it's for military and aerospace purposes. I left out the voltage, currents, power, and frequency information out because I'm more interested in the general fabrication of these devices. I was hoping that there's some general 'rule of thumb' knowledge that others may have regarding this technology. For example, when cutting out the cavity, "do _____, don't _____". At this point, I'm still in a research stage and so I'm trying to find the pros/cons of this technology. I understand there are limitations, but the company I work for would like to know if it's worth using this technology as it may help our reliability in a strenuous environment. I'm in discussions with our board shop, but I thought I'd also try to see if anyone else has experience that they wouldn't mind sharing. As for your application in using planar cores, do you mind if I ask if you have pointers there as well for either the design or manufacturing stages? Also, can I ask what core shape you use? This is also another option we're looking into. Best Regards,Brandon

Further to my comments,  there is some info on the web, here, for example.Cheers,Richard

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EPCOS core, EI configuration. There are a number of application notyes on there web site worth looking at,cheers,Richard