ISO/WTB: Aluminum insert for carbon steerer tubes

[Eric M Cardella]

This might not be entirely bob-ish, but I’m seeking an alloy insert for the inside of a carbon steerer tube. The one reputable option I can find online is sold out: https://www.bigandtallbike.com/Steer-Tube-insert-for-carbon-fork--238mm-Diameter_p_380.html.

If anyone has a lead or recommendation, please share! The use case here is a desire to lighten up the front end of a mixed terrain gravel/pavement bike, coupled with a crippling fear of plastic parts. The aluminum insert would add some weight but offers some peace of mind. 

I should mention that the fork in question has a full carbon steerer, and I expect to maximize the number of spacers under the stem (above the head tube). 

-Eric