Mycelium insulation batts have been a "hope this is available soon" technology for green home builders for at least 8 years (Chris Magwood's 2014 book had hopes for it). Seems like insulation would be the most low tech and first use for it. Hell, we can't even get wood fiber insulation boards in the USA from more than one company at a time.

I certainly materials change, but will I be alive to see it? (til then I'm living like an hippy/hobbit, using plants the old fashion ways).