Paul,
well, if you intend to keep the production machine offline as much as possible, why not stick with Defender for that machine and switch to a less intrusive AV for the office machine? FWIW, my main DAW is connect to the internet constantly, and I disable the WiFi only if I run into issues with DPC latency. And I run Defender exclusively.
And I do not have Office installed on the DAW, that’s what the other computer is for, in my case anyway…
Good luck! Keep us posted!
Benji