Not an STI but the exterior tS badge is tuned by STI   😄   https://www.autocar.co.nz/subaru-wrx-2-4t-ts-spec-b-has-arrived-in-all-its-manual-glory/

Did you ever get the reverse camera to work?   I'm doing this same install currently and have everything except the camera working. I got a factory camera retention cable that changes it to rca, but am still getting no signal. It's driving me crazy. Apologies for reopening a dead thread.

I wouldn't use anything petroleum based, but perhaps something more like sil-glyde. 

I received an order from Amayama last week, split between Japan and UAE warehouses. I can't believe how cheap S&H from UAE was. Packing was great. Shipping time was good. Excellent option for us. 

Only sti specific stuff I know of is DCCD and G-force sensors.   working on some PCB design bits and updating to use the newer canbus chips.   Adding a thermocouple circuit as a test and they cost way to much.