I’ve melded the Dial Mount with the Snapmaker Quick Swap Tool Plate and added using a Helicoil M3 insert so that the threads are more robust. I really don’t like the idea of metal type threads in plastic, it’s much too easy to damage the threads—for that matter, any threads in plastic is a poor idea, IMHO. The Helicoil kit I used is less than $17(USD) on amazon.
Two versions, one with the original size 8mm hole for the indicator and one for a 9.5mm diameter that fits my old dial indicator and my new digital indicator, a Mitutoyo 543-782B. The new one is intentionally a very snug fit. I've included the Fusion 360 Files.
Note that the Quick Swap width may require adjusting as the fit is critical, use shims as required.
An M4-16mm hex key bolt will only be 3-4 turns longer than is required.