My question is really simple: if you have your custom rig installed as a cybernetic augmentation, what is the 'augmentation level' of the custom rig? I'm mostly asking because I was considering the cyberborn theme, and it would be nice to select the custom rig as my cybernetic augmentation (my assumption is that the custom rig's level is equal to my character level, but I wasn't sure).
"Can be installed as a cybernetic augmentation system" doesn't necessarily tell me it is a cybernetic augmentation for any other rules purposes. I think it's just that you have to either hold it (bad for free hands), install it in an armor (bad for free upgrade slots), or install it in your head slot (bad for head augmentations that arne't datajacks).
You're choosing which sacrifice to make in how you manage your custom rig, but you don't get any benefit from it when you have an ability that effects a tech item you're holding (it's not a tech item with an item leve), an armor upgrade you're wearing (it's not actually an armor upgrade with an item level), or a cybernetic system you have instaled (it's just filling up a lot - here the "cybernetic" aspect would only matter if you have an ability that lets you double up with a cybernetic item in one augmentaiton slot, for example as a Verthani who wants their custom rig and a brain slot magitech or biotech augmentation, this would work).