Problems with the size of Programms (HiDPI)

It depends what you want to scale. Moksha scaling only affects Moksha. Since the topic says programs tho, it's not so simple cuz so many different types of programs are supported on linux and Bodhi allows use of them all.   And unfortunately, it's not super simple if you're new at this.  For example, for apps using elementary toolkit, you can set fractional scaling; and easy way to get to those settings is right click in terminology and go to settings/toolkit, or set the "ELM_SCALE" variable.  You may mean programs that use the GTK toolkit, and those we don't have a GUI for scaling. You can set environment variables that affect GTK apps tho, the easiest way is using Environment Variables in advanced settings. For example, set "GDK_SCALE" to 2, and apps will be huge, really only useful for hidpi monitors, as it doesn't support fractional values.  You can scale text in GTK applications with "GDK_DPI_SCALE" and it does support fractions, so if often if you set GDK_SCALE to 2, you may want to set GDK_DPI_SCALE to 0.5.   For apps using QT toolkit, there is a different set of variables.  For electron apps like discord, you can add "--force-device-scale-factor=1.5" for example to their exec line in desktop file.  The archwiki has some useful info regarding how to scale various apps wiki.archlinux.org/title/HiDPI.

I can explain any of this step-by-step or in more detail if its unclear or you mention which app you're trying to scale.