If I were pulling a 5m sheet on my own, I would try a pole along the edge I'm pulling, like you would find on a window blind. A product called 'pvc weld' resembles glue, but actually melts surfaces together. It would fix pvc poles to pvc sheet, very permanently. Where I wanted ropes, I would gaffer tape the sheet before ripping through. Gaffer tape surfaces are very 'rip stop' but gaffer adhesive dries up eventually. This is not a permanent build. Just sheet kept flat with rocks, while a pipe painted with sticky is dropped on.
One would lift the pole towards head height perhaps, using a telescopic washing line prop to keep it there. Then hoist it over the last bit.
The pole could be substituted for bamboo canes and gaffer. I think keeping the edge straight, could reduce energy spent on getting things out of shape, then recovering. While maybe offering a little more wind resistance to flapping about.
With no hands on experience, I could be some way off the mark. Perhaps the 5 meter length could be indefinite, using the right pipe and multiple prop points. So I could gradually ease it up along the length of the house. Or maybe the pipe weld would harden off the sheet. causing early fatigue. It can deform plumbing fittings. It's not messing about. Use sparingly is no joke.
Motor control on the pram roofs, might benefit from tilt switches. Like filling tanks, you do it on timer, with a slight over-run. So the float switch really controls the stop point, and the timer is just a second stop, if the switch fails.
It's very easy to set a tilt switch in a milliput resin case. Which in turn is set to a bar clamp. Perhaps using it to disconnect power to a short range timer. So you would have your mains powered segment timer, powering a precision short range timer used for fine adjustment. Which switches the main with its relay output. But the short range clock side is powered via the tilt, to stop the count completely.