I'd start by looking at the dependencies, here, https://github.com/obsproject/obs-studio/wiki/Install-Instructions under Linux.
The level or quality of the assessment is leading indeed. For the quickest assesment you could assume that there's no matching. documented OpenGL library for OS/2 yet, and stop. If I'm asking you to port something, because I don't have GCC installed, then you may stop right there. No OpenGL. A next level would be to check that the documentation is right. If so, then can OpenGL be ported. If so, quickly?
A starting point could be upgrading existing ports. A next step could be a port which requires a minor change (like replacing <win.h> by <os2.h>), or a port which requires a library you don't have installed yet (as you may have noticed, mister Ko tends to release several libraries, with source code and changes, before releasing a new version of VLC, so you can assess what he's doing w.r.t. those required libraries).
If I'm requesting a port, then I'll take "Sorry, no OpenGL" as an answer. An example of all of the above may be Xpdf. You could try to port and release some of the EXEs of Xpdf easily, an assessment by compiling and an existing real request of me, but you can stop when Qt is involved and when it gets too difficult for a very quick "compile-only"port. Even for Elbert Pol.