Bike porn

As is always the case, It's been done before.
Pace research did the exact same thing on the very first RC 1OO mtb over 2Oyrs ago, before aheadsets were even invented.

ha, ya beat me to it.
and yup, pace used to drill out the threads in the topnuts of headsets, feed the steerer thought, with a bolt in the end and a nut which sat in the underside of the fork, tighten nut= tighten steerer.