No, sparky.
The ports tree contains
infrastructure for building ports, not the ports' source code, and each leaf of the tree contains a series of OpenBSD-specific files/folders specific to that port, such as a Makefile, a distinfo file, and packing lists and installation messages in pkg/*, as well as optional patches/* or files/* when needed for OpenBSD uniquely.
Your choice with custom applications is to either:
- build them outside the ports system entirely
- "port" them.
The latter is what the porter's guide you were looking at is for.
Please read FAQ 15's sections on ports very carefully.