How to coordinate font size, zoom, Auto Zoom, etc.
MultiMarkdown Composer version 2 has a much more flexible approach to displaying your words on screen. In addition to choosing a default font typeface and size, your chosen style theme can override the defaults with alternate font face/size combinations. You then also Zoom In/Zoom Out to make the words bigger/smaller on screen. Auto Zoom adjusts the display size to match the size of the window, so that you can make better use of Full Screen Mode.
My first recommendation is just to experiment and use whatever works for you.
If you insist on a more structured approach, then you could use the following:
(NOTE: --- remember that many of these settings can be overridden in the style themes. The "Plain" theme intentionally does not make use of any of these features so that you have control of the settings. Other themes may have some defaults designed to give a certain appearance/layout.)
Choose a font typeface that you like, and a font size that seems appropriate to you when printed. If you don't ever anticipate printing, then it doesn't matter and pick a default size that you like onscreen.
Adjust the "Default Zoom %" in the Appearance Preferences if you want new windows to default to a certain zoom level. For example, you want your documents to print in Times Roman size 12, but your vision isn't great and you find that a 200% zoom makes it easier for you to read. Changing the zoom doesn't change printed output, only what you see onscreen.
You can always Zoom In/Out as needed when you want to enlarge something for easier reading, or to see more of your document onscreen at once.
If you find that you frequently toggle back and forth into Full Screen Mode, you may find the Auto Zoom feature helpful. This will ensure that a fixed number of characters appear in a given line, regardless of the window size. When the window gets bigger, the words get bigger. When the window gets smaller, the words get smaller. The benefit of this feature is that your lines don't change the way they wrap whenever you change window size. You can easily toggle this feature on/off as needed.
If you're working with documents that have very long lines and you don't want them to wrap, you can change the maximum line length to
0. This effectively disables the Auto Zoom feature, and the lines of text will only wrap when they hit the edge of the screen. As you zoom out, more and more words will fit on a given line. This can be useful in Full Screen mode when working with long tables, for example. (Note --- the "Plain" theme can be used to try this out.)
Once you find settings that you are particularly happy with, consider creating your own theme or modifying your preferred theme to incorporate these settings.
MultiMarkdown Composer offers much more flexibility and control over the way that your text files are presented to you on screen than any other text editor we have tried. Once you understand the control you have, we believe you will find it hard to go back to other editors that can't match this functionality.