I have worked in a big company where we made diesel motors, propellers, gears for big ships, big presses and a lot of different equipments. We never use lubricant with bronze, because bronze like cast iron is "self_lubricating". You don’t get precise sizes and good surface finish.
Have a look on a lot of photos or videos on the net of bronze machining and you can see that they generaly don't use lubricant.
Special lubricants generaly mixed with water are used only with hight speed machining essentialy to cool the parts in this case.
The brother in law of my daughter is machinist and works as supplier for Airbus and Dassault and other companies. He confirms that they work dry if they want to get precision and good surface finish.
But if you get a good result with your lubricant, there is no problem and the precision for the KP on a Morgan is not the micron.
cf §4.6
https://en.wikipedia.org/wiki/Reamer#Lubrication
