We use them for group social areas on expeditions to avoid midges. So they do work !
We use the TENTIPI Varrie 7 polycotton. Ground sheet fits not tightly but keeps midges out.
They warm up quickly in sun so having the lower vents opens and a bit of roof vent open helps.
I have one of these for similar uses and biking etc. Very cheap and lasted well - no issues - over a year now.
I run Walking, Canoeing and Biking expeditions at work and we have a range of kit. Bronze through to Gold. Vango 65+ are the best.
However, they may not need that size if they are clever about packing on the outside and bottom. Some Bronze young people have bought their own for now and after...
My Mora Stainless has some spots on it and tar residue. I used it to pick off pine resin etc and never cleaned it last use, I know I know.
Meths, paraffin, isopropyl alcohol ??
Today, using it.