From what I can find and addon is at least 4MB or so, the UI API adds about 10MB to your add on's memory footprint when instantiated, and the DI API adds about 50MB. So that's about 64MB if the addon is connected.
The Screen Painter stays around 7MB but that doesn't use the DI API. It doesn't use a "normal" user interface though.
The Advanced Layout Designer always stays about 4MB but the SBOAddOn.exe (SAP's Add-on framework) uses about 80MB and runs while the ALT is connected.
Should I expect that when my addon is running and connected it uses at least 64MB?
Thanks!