Does there exist such a thing as mini-scaffold

I'm looking to create an anti-RSI workstation.

Something like:

(only that particular one happens to be a scam called NEThrone)

Only what I have in mind is hacking together something using maybe a car seat, an adjustable monitor arm, and some kind of scaffolding rig.

I've used scaffolding in the past, and you can build pretty much any structure with just 2 parts: pipes and clamps.

However, scaffolding is heavy duty, designed to support thousands of kilos. It's going to be very clumsy working with this.

I'm wondering whether there exists some lightweight alternative. Maybe tubes that are a quarter the diameter.

So my question is specifically this: does such a thing exist?

I would imagine people would use something like this to build home-gyms.

PS If anyone can suggest some online community that may be appropriate for enquiring about this project, I would be very grateful. It seems to be off topic everywhere. But this SE site is designed for people who are building their own solutions — maybe someone can suggest something?