R2 bike built an open that was geared 2x10 with a suspension fork. No silly parts that came in at 7.08kgs.
Do you have any pics or a link to this? Very impressive if indeed there are no "silly" parts (although the definition of "exotic" and silly" seem to vary a lot to weightweenies here!)
Regarding the "exotic" discussion, I feel if something is the lightest on the market and is pushing the boundaries of materials and design then it is exotic. If it wasn't then what on earth can exotic be to weightweenies?
Something being custom isn't exotic by definition IMO either as plenty of cheap, common, heavy things can be tuned slightly for minimal expense or difficulty.
If the part has numerous caveats to it's use or requires a lot of care which makes it of limited practicality to the majority of MTBers then it is exotic too IMO.
Something like an Extralite stem might not be "exotic" for many people here but the sheer light weight, pushing the boundaries of alu stem design, high cost and care required to fit and maintain make it exotic in my eyes. Since the manufacture say that the stem bolts need to be loosened during the winter when it won't be used to prevent stress corrosion that is high maintenance. I want to ride year round and don't put the bike in the shed come winter! Therefore, pushing the boundaries and some limited practicalities = exotic for me.