Laying an 18-meter drainage pipe - special procedure required?

Hello,
there are 2 buildings on our property.
One has a sewage connection, the other is supposed to get a toilet and be connected to the existing sewage pipe.
It is a hillside property - the house with the existing connection is about 4m lower than the one without connection. The future distance between the downpipes is about 18m.
The slope has a step in the middle, see the following sketch.

How should the drain pipe (marked in red) be best laid?
Like this?

Or better like this?


Version 1 would be easier to accomplish because less deep digging is required and we have a partly rocky subsoil.

Question:
Is it a problem to have an additional step in the run?
A 110mm pipe is to be installed. I would use either 2x45° or, if necessary, 3x30° angles.

Is there anything special to consider regarding the long distance of 18m (steeper slope, etc.)?
Clogging due to incorrect installation would of course be very annoying.
Thanks for your tips

version 1 uses 100mm pipes, the horizontal sections have a slope of 1cm per 1m, the vertical sections are 90 degrees, fittings are 45 degrees, from house 2 onwards pipes of 125/150mm lead to the sewer. At the first stage, I would install a 45-degree T-piece instead of the upper angle and lead a pipe vertically upwards with a closure cap, as an inspection/flush cleaning option

version 1 as already described by . Just as an explanation: The slope must be adhered to very precisely (construction laser). Possibly even a notch less. Otherwise, "thin liquid" will flow away faster than the solids can be transported with the water. It is even better to place a small inspection chamber in the "vertical" each time, from which you can clean if necessary. Only a "hidden" vertical drop pipe will not make you happy in the long run. As an extra tip: Do not set the flush tank to the smallest amount of water.