Hu hu hu hu.
Here's the deal. We have support in the form of individual character contribution into the project; Miles has comprehensive knowledge of nekovalkryja maintenance and design, and is fully aware of the function of hemosynth. He's a veteran in the field, and easily one of the most qualified personnel in the setting outside of PNUgen employees and long-time service members within the Star Army who specialize in nekovalkryja design and maintenance.
We have precedent, in the form of Sana Nakamura, who is Yamataian, and was produced to incorporate a synthetic material 'black box' within her brain. She was introduced on the Sakura, rubber-stamped and approved by Wes himself. Everything there has golden admin blessings.
We have continued support in the form of Lorath biomedical technology, which has been proven to circumvent a degree of the rejection efforts made by hemosynth, in the form of the control collar technology, the same technology used by Helen Klein in the design of the Type 29 and Type 27 restraint devices.
We have precedent of the neko body being capable of housing foreign matter, in the form of the Mishhu parasite, which is infamously able to avoid rejection from the neko body, even while being wrapped and intermingled around vital organs which hemosynth would ordinarily have a fit over.
Then there is the matter of Structol itself, in RP being clearly indicated as a 'semi-sentient' adaptive material, which would easily be able to change and adapt to user-specific biology.
Short version is; we have a lot of contributing factors which would support high-end engineered implantation technology, so long as there is (illegal) modification of the neko genetic structure to support it, or, invasive technology which has been seen as capable of overriding the hemosynth rejection feature. Furthermore, if the modus is implanted in a Ketsururi licensed practice; then the neko genetic code can be legally modified on the spot to accommodate the implantation.
Even shorter; get with the program, neko are a post-singularity subatomically engineered species, its about time we gave them a jailbreak.
EDIT: We also have precedent in the form of structural alterations which are able to be made to nekovalkryja via drugs, such as kasserine.