Another update, I tried to reroute LTP1 to COM1 (MODE LPT1:=COM1). Checking mode afterwards states LPT1 not rerouted. Maybe the issue is a part of something else?

Hi, sorry to hear. Did you try Novell DOS 7 (DR DOS 7) already?
I vaguely remember that DR DOS had slightly better printer support.
There's an LPT4 device, for example, which is absent in other DOSes.

What you also can try is to load a memory manager, EMM386, QEMM etc.
Since they are virtual machine monitors, they might give DOS better virtualization capabilities.
It's just a random thought, though. DOS/V does more or less always use EMM386, to fit all the Japanese uilities into DOS memory.

Also, running graphics.com and ega.sys and ansi.sys might make a difference.
The have some effect on how DOS handles console stuff.
Again, might not be a real help. It's just an idea to experiment with.

Another idea: use AUX instead of COM1.
It's a near forgotten alias for COM1 (like PRN for LPT1).
AUX was used on CP/M, that's why DOS still has it for backwards compatibility.
Since It's an alias, though, it might be not so much be hardcoded to COM1.
Maybe DOS or MODE do handle it slightly different to COM1, thus.
Again, just another idea.

Edit: Using DESQView, DESQView 386, Windows/386 or OS/2 2.11/Warp might help.
They have printer spooler capabilities, I think.
DESQView also has setting for communication ports, maybe that helps somehow.
It's just another silly idea, though.

I'd prefer not to install a whole new OS just cause printing isn't working.
Running graphics.com and ega.sys didn't change anything, although ansi.sys did add a line to MODE where CON was correctly identified as 80x24
Reading about graphics.com, it looks like it should enable Shift+PrntScr, but I do have a dot matrix printer so no graphics capabilities there.