Yes. PulseAudio support is for playback only in any case.
The first choice for audio system for Ardour should always be ALSA directly unless you have a specific reason to use Jack, which would be the second choice.
I see PulseAudio as a convenience option, it it’s generally not recommended.
Note that ALSA will reserve whichever audio interface you select for exclusive use.
I also found a button in Ardour, which tells us what synth your using for the midi files.
I am using the general midi synth made by Robin Gareus.
So the install of that synth is now confirmed working on openSUSE and Ardour picks it up automatically.
You only have to select it in Ardour when importing a midi file.