My condolences on the tiny tools you have to use
I think it might be necessary to write a complex trepanning cycle. If your lathe will execute it, use a G81 cycle to peck and break the chip frequently. You might have to alter the peck clearance parameter in order not to waste too much time cutting air.
Peck in about .020" with a tool about 1/16" wide. Chip break every .003 to .005 thousandths. Do this initial penetration near one side of the groove, but leave a thousandth or two for final cleanup. Then, retract and begin the cycle again near the other wall of the groove. This time, you can go a total distance of .040 from the top.
Keep doing this staggered cut all the way to the full depth. The idea is that you cannot make a perfect enough chip to come reliably out of the groove for a full .190 plunge. So the staggered cut makes the groove wide enough to get the chip out.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)