I do not recall a way in macOS to set size of text and as for BeagleIM text size, we are using default size for macOS. I do agree that on large screens it may look small but that is how macOS sizing of text was implemented by Apple.

To be clear, I'll double check size of the fonts used, but I do not want to add a new setting for Beagle to control text size. We have enough settings and maintaining that is not the easiest thing, so I would prefer to keep it simple. Because, if we add setting size of text, then we need to decided what should be using those sizes, etc. - we would need to draw the line. I would prefer to keep things simple and do what other apps do.

The best thing would be macOS having global option "text size" (AFAIR there is one in iOS in accessibility) that would simply solve the issue.

Weird thing is that Apple is (obviously) inconsistent here, and Notes.app does have text size option...

Yes, that is weird, especially as almost all UI on the macOS is SwiftUI based and uses larger controls very similar to iOS controls..