I would like to only launch ibreoffice-writer
What is the problem with right click on LibreOffice icon in dock and select File - Text Document which starts soffice --writer?
Where do you see that option? See the image attached.
I created a simple text using vim (or vi) use sudo:
#!/bin/bash
# Your command is next. Use your own path.
/Applications/LibreOffice.app/Contents/MacOS/soffice --writer
Called it whatever-
Make it executable chmod +x
Made an alias and put it on the dock between trash and downloads (You can’t put it on the normal dock)
Everything works fine, with fewer memory problems.