Yes, BabaCAD can run as portable app cause it use no additional resources from system ones it is installed. Delay of about 2 sec after start is caused by loading hatch patterns from bcad.pat file which is located in Support folder (everyone can test this, just open bcad.pat in text editor and delete all except few pattern definitions, and then restart BabaCAD).
I never thought of BabaCAD as portable app, but it's fro sure 100% portable, and I suppose that you a not the only one who realized that, but first who mention that fact on this forum.
I searched on google and find no pro CAD software on Windows portable app list. I hope someone will edit wiki page and add BabaCAD to this list:
https://en.wikipedia.org/wiki/List_of_portable_softwareGreetings to all BabaCAD users