Judging by this thread it seems my RPM is probably way off as suspected. Intresting point about brushed vs brushless and power vs speed control.
Think I can justify springing for a Makita and retiring the Katsu to handheld use (don’t fancy taking the tool on and off the CNC) at this point, the Lowrider is proving a valuable tool.
This whole thread is a pretty resounding lesson in buy cheap, buy twice 
On that note, I’m off to eBay to buy a “lightly used” Makita for not much cheaper than a brand new one… 