Hi Vanne,
It has side half cutting so we call WETQFN (wettable QFN ).
For the R1 position, it is half cutting process by a sawing operation ,I think it can not be measured .
For round corner R2 & R3 ,due to they produce by the etching process produce so they also can not be measured.
These corner R in the drawing we still define R0.05 but actually our vendor can not control them.