Again I changed everything because I noticed I can add SFX PSU support without increasing volume. So there will be a mounting panel that allows to install SFX PSU or DC PSU with battery. This opens up the possibility for high performance builds > 330 watt and I don't rely on DC psu exclusively. It will also be easy to switch between SFX and DC plus Battery.
To fit the SFX psu the mainboard I/O panel and gpu ports have to be on the left side. I think for a mobile case this is actually good and I think I managed to keep it aesthetic.
The new layout also allows 300 mm gpu with only a restriction in height. So now the case could fit something like watercooled i7 8700K with EVGA 1080 Ti SC2 and Corsair 600W psu.
Maybe 240 mm AiO is difficult now because I need space for LCD Controller and SSD's. So maybe I go with 120 X 45 mm AiO systems like Silent Loop 120. This certainly should be enough cooling. Even for modest overclocking.
Overall dimensions now come close to a machine like MSI GT83. It has the same footprint while only being a little higher on the tapered side. But it has a palmrest so it should provide good ergonomics.
And here is a picture of the new (and hopefully final) layout:
I realy like this new layout with the possibility of SFX psu. I think now I can go deeper into details.