9kg is around the ceiling for a lot of frameless packs. If that's base weight and you then add four days of food and water, you're at 13-14kg, which is past what most of them do comfortably regardless of technique.
Weighed everything separately and the odds and ends came to 1.6kg, including a 210g first aid kit that is mostly packaging.
Fair, and I do enjoy them. It's that four nights of food on top puts me near 16kg and that's where my shoulders start complaining.
The foam pad also gives you a sit pad, a groundsheet for cooking and a backup if the inflatable punctures. Best value 200g in the pack, and it rides on the outside so it costs no volume.
Take the tarp and inner, with caveats.
Midges make the inner mandatory and you already have one, so the real question is pitching. On the west coast you will nearly always find peggable ground. It's boggy rather than rocky, and the problem is pegs pulling out of soft ground rather than not going in. Carry six proper Y-stakes instead of the wire ones in the box and you're fine.
The 440g isn't the main advantage anyway. The main advantage is that a pole shelter pitches taut in wind once you know how, and packs away wet without contaminating the inside of your pack.
Caveat: practise the pitch in the garden at least three times, once in the dark. Pitching a pole shelter badly in wind at 10pm surrounded by midges is genuinely miserable and it's the failure mode nobody budgets for.
Worth ruling out fuelling. Most people have a coffee and a sandwich, walk hard, and feel terrible at 2pm. Eating properly early on day one is unglamorous and it works.