Beautiful design. Curious since you mention the issues with plastic, what's the part that you couldn't avoid plastic for the trefolo (given you mention it's 0.01% plastic)?
A huge pain to install as it's so stiff and needs special tools and fittings to keep it from absorbing water from the air. It has a large bend radius, and it only good for fixed installation as it will crack open if you bend it a few times. And it's nearly £1000 for 100m. So it's not very popular these days.
Plastic really is an annoyingly wonderous category of material when you consider the flexibility, insulation, mechanical, thermal and chemical resistance it can have (and the price)!