Design for iOS - how many screen variations should a designer draw?

Question

iOS

There are many design guidelines for different iOS devices. For example, here is a beautiful one - www.paintcodeapp.com/news/ultimate-guide-to-iphone... However, none of them (that I read) say how many different screens a designer should draw.
Should a designer for each screen size in points (320x480, 320x548, 375x667, 414x736) in a good way make a separate layout in x2 and x3? And what about the font sizes - they are also prescribed separately for each of these 4 screen sizes?
Or do they make different layouts with different font sizes for 3 different screen widths (320, 375 and 414), and usually don’t bother with verticals (they try to fit into a smaller screen, and then everything will fit on a larger one without scrolling)?
And if we draw only for the smallest width (320) and for the largest width (414), then we can indicate somewhere that for the average width (375) we do not want to compress from 414, but stretch from 320? Is this iOS determined or the developer?
Can we change font sizes based on screen size? Should we do this?
If you are too lazy to answer, but you know where you can read it - send a link! I read English without problems.

Answer 1

Draw at 4/4S, then at 6 and 6+ to see how it will look on these screens. Stretching and "thinning" is always easier than squeezing and compacting, so you should start with the smallest of the supported screens and work your way up to the larger one, not the other way around. Often, a layout that looks great on a 5/6 screen turns into complete darkness on a 4/4S screen. It is clear that we are not talking about banal cases such as a table - we are talking about complex screens, divided into several areas.
Usually you want to shoot a designer with a slingshot who draws a rich complex layout in 5/6, and then you either sit and try to shove it onto a 4/4S screen, or take a break for several days that no one needs, waiting for reworked layouts.
As for the font sizes, they should not change depending on the screen size. They can (i.e. technically achievable), but they shouldn't. Apple assumes that they will not change.