Defrost gets a whole section to itself within the engineer's menu. I found it was a bit aggressive for our location so have shortened the duration and extended the minimum time between defrosts. Plus the ambient sensor was a bit too close to the evaporator which didn't help...
Don't think I've seen this posted before- it's a more full and descriptive guide to the settings on the Carel
https://sprsun.nl/wp-content/uploads/2022/07/Function-description-of-DC-inverter-heat-pump.docx.pdf
They're a local supplier, but the kit will be Garador or the likes. Can't assist on pricing as it was included in the cost of the shed.
The two guys were here for a couple of hours. There's not much to the install, you could happily do it yourself. A lot depends on the squareness of the opening tho...
The one in Nods photos is the same as ours, supplied for our shed by Garage Door Systems
https://garagedoorsystems.co.uk/products/insulated-roller-doors/
foam filled slats, brush seals at the sides etc
Flexis are recommended regardless, but yes either a formed bend or a radiussed bend fitting instead of those elbows. Personally I'd try to minimise the number of those pressed fittings used where possible as their ID can be surprisingly small...
you'll need to help us a wee bit here- pushfit and solvent are different sizes, but some compression fittings can span both, not really a "brand" thing. What exact sink trap do you have there?