What are the benefits/drawbacks of using longitudinal tables in Qlik?

[#1]

I am making an app with Qlik Sense, I will use an incremental load and the data will likely change over time (new metrics added). For maintenance reasons, I thought of storing the table longitudinally (DIMENSIONS|METRIC NAME|VALUE) but I am not sure of the implications of such an approach on the visualisation side.

The doubts wandering my mind are:

• Is there any chart that cannot be achieved by means of set operations because of a longitudinal table is being used?
• Is there a big computational weight associated to the use of set operators in the visualisation side?

As a side note I read the presentation attached to this document Performance and Optimization Best Practices in QlikView & Qlik Sense and I understood that the memory usage of the data depends on the unique values included. However, I loaded 300k rows times 60 variables both in wide and long and the memory difference is around 50% (16000KB wide format vs 24000KB long).

• Does this difference became smaller as data grows?

I include a minimal example in the attached QVF.

Any advice is welcome.