Tiles on a half-spiral staircase - who has experience with that?

Quite simple and would have of course looked good. Now it's a mess.

That would also have been a mess with this tiler, because he would have alternately started on the right and left, i.e. with the steps going into the corners having a severe offset compared to the previous / following ones.

Therefore I meant: to lay a 60 cm strip in the walking line, i.e. on the side of the spindle consistently with 20 cm "remainder" on the tread steps, and to proceed the same way on the riser steps (or offset by 30 cm).

And then safely sketched out beforehand (so as not to be surprised that 18 or 22 cm spacing on the spindle side would have avoided another joint).

Oh dear, that looks terrible... he probably tiled a staircase for the first time in his life.

That would have been botched by this tiler as well, because he would have started alternately on the right and left, meaning at the steps going into the corners with a severe offset compared to the previous / following ones.

One must not be completely stupid.

That’s why I meant: to lay a 60 cm strip in the walking line, i.e. consistently on the side of the spindle with 20 cm "leftover" on the tread steps, and to proceed similarly with the riser steps (or offset by 30 cm).

And that is easier, if mine is not supposed to work anyway??

And that's easier if mine isn't supposed to work??

Why shouldn't your suggestion work? - I only said, this tiler would have managed to botch it as well.
Offset - around a common reference line - works and looks good. How this tiler probably would have implemented it (starting alternately left/right, but without considering the different step widths) would not have looked good.

Your suggestion is more universal, mine is specifically designed for large formats.

OK. You probably can't change anything anyway unless you spend money, which I don't see any point in. I hope it looks better once it is grouted in approximately the same color.

Very unaesthetic. Sorry.

I would neither try to align the joints of the treads (doesn't work anyway), nor try to align the joints of the risers with those of the treads.

Always staggered relative to each other.

In hindsight, I would have done it this way: always 60 cm inside, as it is with the straight steps. And the joint on the riser flush with the joint of the tread above.