Is the wastewater pipe for the toilet too far away?

Unfortunately, I did not pay close enough attention to the execution plan. Now a sewage pipe (KG DN100) has slipped too far into the room. Floor plan see attachment. Now we would like to make a corner toilet instead of the straight pre-wall at the WC, but with a Geberit Duofix for the corner (the expensive mounting element - item no. 111.390.00.5 - so that it can be pushed as far as possible into the corner). I don't have an exact number right now, but according to the floor plan the center of the sewage pipe behind the WC should be about 62 cm from the outside wall. There will be 16 cm of floor buildup on the raw floor. Could someone tell me based on the data whether it is realistic to bring the small Geberit corner element into the corner at the outside wall and still ensure proper drainage (is it possible to achieve the slope over that distance)? Or should I rather take a normal Geberit Duofix element (item no. 111.300.00.5) and install it diagonally in the corner (which would push everything about 12 cm further into the room, but I would get somewhat closer to the sewage pipe)? It is somewhat urgent, as I would have to order the mounting elements by tomorrow at the latest.

If it is a floor slab and the KG pipe is fixed, a 90° HT branch was planned. Then you will probably have to build a pre-wall even for a corner toilet because you won’t reach the height. Or lay the shower perpendicular to the second waste pipe. At about 2m distance and 1% slope, this is also possible. With a suspended ceiling, it is feasible. Chisel out concrete at the spot and set a 45° HT branch deeper so that the top edge of the HT branch is not much higher than the concrete ceiling. Then use an 87° bend and lay it with a 1% slope to the corner.

Ok, yes, that was also a problem, that the connection of the shower would no longer be ensured. Yes, it is a floor slab and we definitely will not break it up for that, I would rather accept the original pre-wall construction, but I have coordinated with the construction company on this and we could lead the shower to the washbasin, but it is about 2.6m distance, not 2m, but it should still work.

I have roughly drawn the pre-wall element with the rotated toilet attached. This is now not the Geberit corner element, but a normal mounting element slightly rotated drawn in. If I understand correctly, you should then come almost behind the drywall with two 87° HT elbows and a few centimeters of straight intermediate piece and then somehow get to the connection of the WC. But isn’t that too many bends?

- the WC element already makes a 90° bend downwards at the outlet
- then it goes a few centimeters straight down to just above the finished floor
- then an 87° elbow to the right to the connection in the floor
- there comes the first 87° elbow that is embedded in the floor
- a few centimeters of steeper slope to the second 87° elbow which ultimately leads to the KG pipe in the floor slab
- in the floor slab there will surely also be an 87° or 90° elbow

- with a floor slab, you should not chisel anything either. - if the [Vorwand] is installed, the shower should not necessarily be routed to the washbasin, but the installer on site must decide. - with a 16cm floor construction, a distance of 3m would still just be feasible. - a [Vorwand], whether flat on the wall or in the corner, is needed in any case to be able to lay the ventilation of the drainage pipe.