I compiled the SDLTRS with help from Jens Guenter using ARCAOS.
With the YUM archivemanager I got all software I need in an easy way.

These are the file you need with OS/2. I run them with ECS 2.1 
which is my main system.
The DLL files must be copied into ./os2/dll or you must put the directory into
the search path

23.07.20  3.36         65.864    124 a---  gcc1.dll
26.08.21 13.26      1.229.242    124 a---  libcn0.dll
15.03.16  3.35        301.035    124 a---  SDL120.dll
 9.07.22 16.18            376      0 a---  sdl4os2.txt
10.06.22 13.44        619.388      0 a---  sdltrs.os2.exe
        
Keyprssing makes sometimes problems as you got more chars as you need.

In XTRS and SDLTRS there is the option -keystretch (in the SDLTRS GUI under 
"Miscellaneous/Printer"): please try smaller (e.g. 400) and larger (e.g. 40000)
maybee it will help