I run them at higher RPM... 6000 as a rule.
For chamfers, I run at 35 IPM. Any higher than that and I start seeing vertical lines in the chamfer.
I offset the Z down as far as I can without causing a secondary burr... avoid the tip and keep the top of the 45 degree portion above from the top of the part.
For plunge spotting, I back the RPM down to material specific SFM and back the feed way down (.001 IPT).
To a large extent, I have drifted away from using spot drills for the above operations. I find that I get better tool life and finishes using a 45 degree Drill-Mill... you know those stupid endmills that have a 45 degree tip. I always figured they were for people running Rong Fu conversions that wanted a 45 degree cutter but also wanted to do side cutting in case they forgot to change tools
Turns out they run great in aggressive CNC applications.