Some years ago, I bought a wood router( I think that the USA is a planer) but it was a Bosch POF 50. When I got it out of the box, I found the notes to suggest that it had started life as a tool post grinder. And there, I returned it to its former purpose with a 43mm collar on the lathe saddle.
However, the trick is also the 43mm collar because it accepts quite a number of battery and mains electric drills.
Clearly, the centre should line up with the lathe centre height.
What one has to remember is that Double ended grinders are usually fitted with poor bearings for this tool post duty and limited to 2880rpm, therefore this is far too slow for a tool post grinder.
Don't get me wrong about DE grinders, I have one which ended up driving a basic tool and cutter grinder which was a modified three way vice.