Do others see it slightly illogical that I can add condition to every subquestion in checkboxes-type question, but not for items to be selected in ranking-type question?

It's because options in a multiple-choice are "sub-questions", therefore each have a column in the data. Options in a ranking are "answers", therefore stored in another table.

Currently you can only apply relevance/conditions to questions or sub-questions in the data table.

An alternative is to use an array filter to hide/show the answers. Joffm has given many examples on how to do this with hidden questions.

Yes, I do understand the technical viewpoint of this. But from the users perspective it can be confusing, I guess.

array_filter is a good idea for many cases, but not for the one I was asked this time.

It is certainly something that many of us wish for (answer relevance), there is probably some feature request for this somewhere as well.

However, resources are limited and the question/subquestion relevance is also 'relatively' new to Limesurvey (just a couple of years).

holch wrote: However, resources are limited and the question/subquestion relevance is also 'relatively' new to Limesurvey (just a couple of years).

True, I do understand. And we usually forget to say thanks, so for at least once: Great software! Thanks! And also thanks to thos who have answered my questions and bug reports here.

The subquestion relevance was one of the biggest steps ahead for Limesurvey in the last couple of years (before the expression manager in general was a very big deal).
Unfortunately in my opinion, there was very little real progress in terms of features and functionalities. Unfortunately the changes to the GUI have caused a lot of work and trouble and in my opinion have not been the sucess that I would have expected.
Now once LS 4.x is more "under control" and finally the template/theme system is stable, we might see more real progress in features.