Batch-remove mkv titles only, no re-encode
I was a bit unsure about trying a Java GUI app add-on for this, but I got it going reasonably easily.

Linked from MKVToolNix's GUIs and batch operations page I found JMkvpropedit

I couldn't initially persuade it to see the mkvpropedit binary inside MKVToolNix, either from its own file-picker dialog, drag &amp; drop or even editing the file path [it won't edit or paste], so like a true newbie, I just copied it out of the app's 'Show Contents' into my Apps folder - tadaah! Now it can find it &amp; use it.

After that it was simple.
Drag set of files onto the Input tab.
On the General tab, check Title &amp; add {file_name}
Click Process files.
Done in seconds.